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KPNO MOSAIC-1.1 IMAGER USER MANUAL Version: 4.3, February

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1. EE 19 2 TRACK 20 2 05 FOR MOSAIO ee 20 2 7 OPERATION OF THE GUIDER TVS enne nnne rehenes ene 25 20 CORRECTOR 26 2 9 ATMOSPHERIC DISPERSION CORRECTOR THE A MONLNT 28 20 SOFTWARE isi 31 THE MOSAICSL COMPUTERS 54 a 31 9 2 4 31 3 3 LPHEINS AND OUTS OF SCRIPTING 39 44 3 DITHERING mrisani ____ __ __ _ 48 3 6 SHUTTING THINGS DOWN AND RESTARTING 52 40 EVALUATING RECORDING AND REDUCING MOSAIC IMAGES 53 4 1 WORKING WITH MOSAIC DATA FILES sU 53 4 2 DISPLAYING AND EVALUATING IMAGES AT THE IELESCOPE eee nene 55 AS EXAMINING THE DIM e 56 4 4 GETTING YOUR MOSAIC DATA 58 4 5 THE REDUCTION OF MOSAIC IMAGES 26 4 6 CA
2. ENEE File Help Quit Process Status Shared Cache Real Tine Display Paths 8 Files Shared Cache Status shmiId Delete All Update Status Process Process All SHC Page Usage nosaicidhs 01 nosaicidhs 01 Disk Usage 53 Connect Status Exp Status J MM M M M Figure 49 DHS Shared Memory Cache window 70 pu MM M M M M M n Data Handling System Supervisor File Help Quit Process Status Shared Cache Real Tine Display Paths 8 Files ptions DetNane nosaicl 550 75 nosaicl 543 92 609 00 nosaicl 500 00 660 00 nosaicl 546 00 854 74 nosaicl 278 00 637 81 nosaicl 150 00 311 00 nosaicl 310 00 612 81 nosaicl 399 10 727 43 SHC Page Usage nosaicldhs 01 nosaicldhs 01 Disk Usage 53 Connect Status Exp Status Figure 50 DHS Real Time Display window NMSL Mosaic 1 1 Die Options pts LIESE ocal Plate Temperature too LOW Temp 106 Connect To rmocouple temp1 106 599998 rms li 5 ocal Plate Temperature too LOW Temp 106 60C nmsLi Disconnect From rmocouple temp1 106 300003 rms Li ocal Plate Temperature too LOW Temp 106 306
3. Refresh Filter s Set Project Exit l v20101011 2010 AURA Inc Contact Philip Daly pnd noao edu Figure 40 The NGUI with buttons at the bottom for script configuration 2 3 4 5 6 7 8 9 1 al 1 1 1 LA g 2 0 3U 4 39 There are NOCS scripts for zeros darks focus frames test exposures dome and twilight flats objects and Mosdithers and Mosgrids see figures 52 60 Clicking on any of the buttons at the bottom of the GUI launches a script configuration window with options specific to that type of exposure For instance clicking on the Zero button launches the Zero Script Configuration for writing a script to take biases Figure 41 You can edit the Object Name Script Name Number of Observations NumObs and binning factor Note the Integration Time intTime is set to zero See Appendix E for a complete listing of all of the script configuration windows RO ZERO configuration SCRIPT CONFIGURATION Object Name ZERO Observation 7 Script Name 210 OBSERVATION CONFIGURATION e Biv Riv tlw nately tly 2 93 se 95 val MONSOON CONFIGURATION intTime sec Binning 1x1 2 2 Figure 41 The ZERO script configurations GUI used to create scripts for taking biases To save a script simply click OK at the bottom of the window If a script with that name already exists yo
4. R 23 24 37 89 OSDITHER 101812 jPn8 23 23 42 96 OSDITHER 101813 23 24 24 22 SHC Page Usage nosaicidhs 01 nosaicidhs 01 Disk Usage 177 Connect Status Exp Status Best focus estimate 3335 26 4409 18 Best focus estimate 5127 02 3709 26 Best focus estimate 8 4928 18 3526 14 Best focus estimate 4744 76 un 2 98 Best focus estimate 8 2826 89 7104 12 0 30 Best focus estimate 8 3195 21 7223 25 1 74 estimate 8 2670 98 6308 18 0 86 f 9643 23 23 56 74 R 23 24 10 46 Best focus 101802 at focus 9154 with average FWHM of 2 29 101802 at focus 9254 with average FWHM of 2 77 101802 at focus 9354 with average FWHM of 2 89 101802 at focus 9454 with average FWHM of 3 22 n101802 at focus 9554 with average FWHM of 3 45 101802 at focus 9654 with average FWHM of 2 79 101802 at focus 9754 with average FWHM of 4 10 Average best focus of 9396 73 with FWHM of 1 89 ecl gt Wi ae NN xgterm mosaiciInl collector collector smemgr config xgterm Figure 28 The Mayall 2 right hand monitor with necessary windows shown the DHS VNC window and autolog And the top monitor should look similar to this mayall 2 VNC 4M VDU
5. 106 70 Set Logain Mode Figure 51 NMSL Options menu 71 X MOSGRID Observations 000000000000 cript Nar MOSGRID OBSERVATION CONFIGURATION SMM cS EP EG Dm P v 8Q RAxDec From File ET E aso 2 E 2121 Guider wait 9 Random RAxDec From Pie 2 OK gt Figure 52 NGUI Mosgrid configuration window N MOSDITHER EET MOSDITHER Observation s MOSDITHER OBSERVATION CONFIGURATION Figure 53 NGUI Mosdither configuration window Observation s OBSERVATION CONFIGURATION OK Cancel _ Figure 54 NGUI Object configuration window X TFLAT Observation s OBSERVATION CONFIGURATION OK Cancel Figure 55 NGUI Tflat configurations window 72 X DFLATS Observation s DFLATS OBSERVATION CONFIGURATION OU dadada la da da ixi 2 2 1 ze 1 1 22 4 2 2 OK _ Lamp Prompt Cancel A Figure 56 NGUI Dflat configuration window Gg Fc p TEST configuration TEST Observation s OBSERVATION CONFIGURATION OK Cancel Figure 57 NGUI Test configuration
6. 6 VR Low53V 30 Low 100 _ 10s __ Bw SO wh 5 7 Low506 7 Ua High53V 25s _ Table 13 Approximate dome flat settings and exposure times 10s 2 95 22 Low 53V Low 10096 0 0 2 68 9 0 APPENDIX 5 Menus and Windows in Detail Below are snapshots of various menus and windows within the NOCS system for reference EN An Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking Checking 4 exec status all Data directory data2 observer 20101023 mosaiclpan a 4m kpno noao eduzzpanDaemon mosaicipan a 4m kpno noao edu zpanCapture mosaicipan a 4m kpno noao edu zpanProcflg mosaiclpan a 4m kpno noao eduzzpanSaver mosaici 4m kpno noao eduzemsl mosaici 4m kpno noao eduzzmslSuper mosaici 4m kpno noao eduz mslSent mosaicl dm kpno noao eduginics mosaici 4m kpno noao eduzentcs mosaici 4m kpno noao eduzznohs mosaicl d4m kpno noao eduginmsl mosaicl 4m kpno noao edutingui mosaicl dm kpno noao edugtdhs mosaicl d4m kpno noao edutipym mosaicl d4m kpno noao eduttsuper mosaicil 4m kpno noao eduttximtool mosaicl dm kpno noao eduttvneviewer mosaicidhs 01 4m kpno noao
7. At UBVRI 20th mag U 2 B 14 V 15 16 1 9 59 59 XIMTOOL Orientation North left East up 0 43 pixel Scale present per degree C Table 4 WIYN 0 9 M Characteristics 14 All ofthe Commands That Are Likely Be Needed Observing Commands nocs status all displays the status of all NOCS processes nocs start stop all starts or stops the NOCS observing program nocs stop start mccd opens or closes the MCCD and ADC windows nocsMode logain sets the gain to logain mode nocsMode normal sets the gain to normal gain mode nocs set project after the program ID has been set in the NGUI this updates the headers nocs start stop opens or closes the window nocs start stop ntcs opens or closes the telescope control system interface nocs start stop nics opens or closes the instrument control window filterwheel etc Quick look Commands mscexam general tool for examining image mscdisplay display an entire Mosaic frame mscstat general tool for looking at image statistics mscfocus IRAF routine to quickly determine best focus from a focus sequence 15 What s Changed with Mosaic 1 1 The purpose of this short section is to provide a list of the major changes in Mosaic 1 1 commissioned October 2010 that will affect the user These changes are the areas of observing strategy data transfer and storage and operating the camera On a casual look a new Mos
8. 34 Taking an Image Before taking any data you should check that your name and your program title go into the headers with the correct information Select Set Project at the bottom of the NGUI Set Project Parameter s Principal Investigator Heidi Schweiker Pls Email Address heidis noao edu Actual Observer s Schweiker AOs Email Address 4meter noao edu Observing Assistant Operator OAs Email Address 4meter noao edu Proposal Identifier 20108 2006 7 Telescope System KPNO Mayall Am Science Instrument Mosaic 1 1 Save Figure 42 The Set Project GUI Enter correct information and click Save Any changes you have made here do not take affect until either you restart the NOCS software or you specifically set the project To do this type set project xterm window that is logged into 1 as observer data is taken by executing a script from within the home observer exec directory See Section 3 3 for how to create a script The progress of a script is shown in the NOCS Status field of the NMSL window see Figure 30 In a sequence of exposures this is where you re current position in that sequence is displayed Finished script will appear when a script is complete 44 During an exposure countdown clock will be green and Status line to right of the countdown clock will display Integrating When the e
9. 50 e2v SN10 02 e2v SN11 01 zi e2v SN11 02 40 2 SN13 01 2 SN15 02 e 2 SN19 01 20 350 450 550 650 750 850 Wavelength nm Figure 3 Quantum Efficiency of eZv CCDs in the Mosaic 1 1 imager compared to a typical SITe device used in the former Mosaic 1 imager All eight chips have excellent cosmetic qualities and very similar performance characteristics Figures 4 and 5 show typical raw images of a bias and flat field The bias frames show an amplifier bounce at the beginning of each row read This bounce is at a 3 5 e level is very repeatable and is removed with a zero subtraction The flat field images show good pixel response uniformity and sensitivity There are three bad columns in the entire array and they are located on CCDs 5 and 8 that are positioned on the outer edges of the array oe SS UO EE Si Figure 4 Typical bias image showing the amplifier verical bands apparent along the columns near the output amplifiers 12 Figure 5 Typical flat field image R band This raw image shows the good cosmetics and uniform response and sensitivity of the devices The rolled off edges are caused by filter vignetting Vignetting Mosaic 1 1 has slightly larger gaps between the top and bottom CCDs due to the packaging constraints of the new e2v CCDs Thus the N S dimension of Mosaic 1 1 s focal plane is sli
10. Mosaic images are recorded in a special multi extension FITS format MEF In brief the Mosaic CCDs are saved as individual images grouped together as separate entities in a larger FITS file only at the end of the reduction are the CCDs assembled as a single large astronomical image Because of this special format most IRAF routines will not work directly on the full raw Mosaic files To provide for processing of the special Mosaic format as well as reduction and analysis tasks specific to Mosaic we have developed a set of IRAF routines available under the MSCRED package Almost all of the software tasks that we discuss in the following sections presume that you will be working within this environment A key factor that drives both the data taking and reduction of Mosaic images is the presumption that the final astronomical exposure will be built from a number of Mosaic images obtained by dithering the telescope This places strong demands on the quality of the data reduction to ensure the uniformity of the photometric response of the reduced image 41 Working with Mosaic Data Files An excellent summary of the Mosaic reduction routines is provided in the two guides written by Frank Valdes Mosaic Data Reduction System http iraf noao edu projects ccdmosaic Reductions and Guide to the NOAO Mosaic Data Handling System http www noao edu noao meetings spie98 mdhs ps We encourage Mosaic users to read through these documents before att
11. but in the limiting case of a large number of images this will only yield 80 of the signal to noise available from an average On the assumption that most vectors of pixels to be stacked will be valid an average with occasional rejection gives the best answer Going all the way through to this stage has produced final stacked images of variable quality depending on the conditions of the observation In non photometric conditions the sky may not be flat further scattered light from nearby objects may affect the sky over large areas Unfortunately the pattern of scattered light varies as the telescope is dithered A further complication is that computation of an average mode for an image may be affected by scattered light that affects only a small portion of the Mosaic field At this time we are still working on a solution for stacking images of this type The solution is likely to require fitting and subtracting a sky surface to the individual Mosaic images prior to feeding them to MSCSTACK When conditions are favorable however we have produced beautifully flat stacked images free from defects showing the full scientific potential of Mosaic camera and providing a suitable reward for our hard work 4 10 ASimplified Summary of the Processing Steps NOTE this section remains relevant for Mosaic 1 1 but is not up to date The next version will have updated information George Jacoby contributes the following sequence It represents as
12. checkReturnValue nics nics filter 3 set dynamic expID OBJECT Observation 1 2 script DflatV sh ditscmd nmsl init ditscmd nmsl_wgui Argument1 OBJECT Observation 1 2 script DflatV sh checkReturnValue nmsl nmsl wgui OBJECT Observation 1 2 script DflatV sh ditscmd nohs nohs_init ditscmd nohs nohs_newobs Argument1 NOCNUM 2 NOCNPOS 1 NOCOBJ DflatV NOCCBIN 1 NOCNO 1 NOCTOT 2 NOCS KY 0 NOCDHS OBJEC T NOCFSN k1003 NOCSCR DflatV NOHS Mosaic 1 1 NOCTIM 45 NOCRBIN 1 NOCFIL V NOCT YP OBJECT NOCID EXPID NOCSYS kpno_4m checkReturnValue nohs nohs_newobs headers ditscmd init ditscmd gpxSetAVP Argument1 expID EXPID checkReturnValue nmsl nmsl gpxSetAVP expID EXPID ditscmd nmsl init ditscmd nmsl gpxGetState Argument1 IGNORE checkReturnValue nmsl gpxGetState IGNORE ditscmd init ditscmd nmsl_gpxStartExp checkReturnValue nmsl nmsl gpxStartExp none end observation sleep 2 ditscmd nohs nohs init ditscmd nohs nohs endobs checkReturnValue nohs nohs endobs none Finished script home observer exec DflatV sh ditscmd nmsl nmsl init 42 ditscmd nmsl wgui Argument1 Finished script home observer exec DflatV sh checkReturnValue nmsl wgui Finished script home observer exec DflatV sh tput bel home observer e
13. logged in to 1 Beware If you indicate a directory that does not exist this will NOT create the directory for you instead it will create AND CONTINUOUSLY OVERWRITE a single file Your images will not be saved At the bottom of the DHS Process Status tab see Figure 45 in Appendix E you can see the directory location and file name of images as they are written to the computer 1 If this window turns red it is indicating that the DHS is in a bad state Most likely this will require a restart of the NOCS software At the bottom of the DHS window is an indication of the disk usage Mosaic files are large 282Mb for an unbinned image and although this is a Terabyte disk it can fill up quickly If the disk is full your images will not be saved In the DHS Real Time Display tab see Figure 48 in Appendix E there is a Display Enable button that allows you to control whether or not the data is automatically displayed upon readout Select this button to auto display deselect it to have no automatic display When an image is displayed there is a constant bias level that is subtracted from the auto displayed image This may occasionally make an image appear odd when 45 automatically displayed Whether not this on the fly OTF bias subtraction is cause of an odd looking image can easily be determined by redisplaying the image in question You can turn this feature off in the DHS Real Time Display tab
14. you have used NEWFIRM this is the same system adapted for Mosaic 1 1 The NOCS is a Script driven system all image taking even a simple test exposure requires a script Some other smaller differences are that there appears to be a lower level of fringing in I or z band Also U band images show a low level 1 2 background pattern that we believe may be related to the thinning process or the anti reflection coating of the CCDs Flat fielding removes the pattern well For the record the read noise in normal gain mode is about the same as with the previous Mosaic system 5 the plate scale and field of view are essentially the same and the QE has not changed dramatically albeit better in the U and B bands Oh and the same filters are available 1 6 Instrument and Data Overview The Kitt Peak CCD Mosaic 1 1 camera is a wide field imager having 8192 x 8192 pixels At the KPNO 4 m the pixels 0 26 on the sky this provides a field of view of 36 arcmin on a side At the WIYN 0 9 m where the pixels are 0 43 on the sky the field of view is 59 arcmin on a side Each unbinned exposure with the Mosaic 1 1 camera requires 22 seconds of total readout time including exposure preparation time and CCD readout when in the default 1X1 normal gain mode When used with 2X2 binning the readout time for Mosaic 1 1 is 8 seconds The CCDs are read out through 16 amplifiers by the MONSOON Orange controller The data are placed on a disk d
15. Note that when using logain mode one needs to manually click the logain button in the DHS to enable the logain OTF bias subtraction Occasionally during a sequence of exposures usually ones with a very short integration time the images appear to get backlogged in the DHS The symptom is that an exposure will finish will readout with no errors or failures and then not be written to disk or automatically displayed in the DHS Ximtool window If the rest of the system is healthy i e no errors or failures the DHS window is not red there is plenty of space on disk it may be that the DHS is not keeping up with the data being taken The images are likely still available and simply need to be pushed through the system We ve found that sometimes this just requires another single exposure to be taken after the current sequence has finished However sometimes this requires more intervention In the DHS Shared Memory Cache tab click on Update Status You should see several lines 16 lines per image added to the text window above this button Often this will be enough to push the images through If it doesn t click on the Process Next button once If problems persist contact your support person or Instrument Scientist Exposure control commands One can change the integration time during an exposure To do so enter in a new exposure time in the New Integration Time s field on the NMSL window click Change Integration Time T
16. Z5 FHEIVIAIN GUT bie b 32 FIGURE 26 THE NOCS MOSAIC STATUS ALL WINDOW sceccececcececcecnccucuccucecucceceecusueceeneeueeeeeeeeaeseeeeeecseesseeeseseesess 33 FIGURE 27 THE MAYALL 2 LEFT HAND MONITOR WITH NECESSARY MOSAIC WINDOWS SHOWN een 33 FIGURE 28 THE MAYALL 2 RIGHT HAND MONITOR WITH NECESSARY WINDOWS SHOWN eene nnne 34 FIGURE 29 THE MAYALL 2 TOP MONITOR WITH NECESSARY WINDOWS SHOWN 34 FIGURE 30 THE NMSL GUI WHERE MOST OF THE EXPOSURE INFORMATION IS 5 35 FIGURE 31 THE NGUI PROVIDES THE CREATION OF EN 35 FIGURE 32 THE VNC DHS WINDOW WHERE IMAGES ARE DISPLAYED eececeecececcececcecnccesuceeeuceseucuseeeeeeeecseeesseeeseeeesess 36 FIGURE 33 A MOSAIC LEGACY GUI DISPLAYING TEMPERATURES A 36 FIGURE 34 A MOSAIC LEGACY GUI ENABLING FILTER CHANGES SETTING OF THE TELESCOPE FOCUS 37 FIGURED 9 THE ADC _ 37 FIGURE 36 AN XTERM WINDOW USEFUL FOR TYPING NOCS COMMANDS 1 666 37 FIGURE 37 THE MOSAIC 38 FIGURE 38 THE TRUSS TEM
17. as an 8192 x 8192 pixel detector array as shown in figure 1 The Mosaic 1 1 CCDs are read out through two amplifiers per chip simultaneously to 16 video inputs of a MONSOON Orange controller The resulting Mosaic array is a square about five inches on an edge The space between CCDs is about 1 2 mm in both row and column directions and corresponds to about 80 pixel gaps in the imaging area Mm 126 4 mm CCD 6 CCD 7 CCD 8 SN13 01 SN19 02 SN15 01 CCD 1 CCD 2 CCD 3 CCD 4 SN10 02 SNO5 01 SNO9 01 SN11 02 Figure 2 Orientation and layout of the CCDs in the Mosaic focal plane at the KPNO Mayall 4 meter telescope 124 0 mm All gaps are 1 2 mm 80 pixels The Mosaic 1 1 Imager is populated with thinned AR coated e2v CCDs The CCDs are deep depletion variant from e2v for improved red response A 2 layer AR coating was chosen for improved blue response relative to the SITe chips used in the previous Mosaic imagers giving a big advantage in overall exposure time about 3090 shorter for equal S N in U band Additionally the 2 layer coating provides more uniform depth in all bands generally limited by U and B and has a flatter response curve to allow easier photometric transformations Figure 3 shows the e2v QE performance relative to the typical SITe CCD 11 e2v Quantum Efficiency 100 90 80 70 60 Typical SITe e2v SNO5 01 2 09 02
18. can use the approved mechanism for modifying parameters within the tasks by typing to switch the focus of the mouse cursor to the graphics window i gets you back to the image and typing to edit the parameters of the sub task being execute For evaluating focus sequence exposures you may use MSCEXAMINE or MSCFOCUS With the former you measure individual widths and keep track of the focus values yourself With MSCFOCUS which is a Mosaic version of KPNOFOCUS you mark the top exposure on any CCD whether top exposure is the double spaced exposure or not for each star and the task measures all the exposures in the sequence and estimates the best focus value using information recorded in the data 56 file To run MSCFOCUS displayed exposure just give command with name it will display the exposure if needed cl gt mscfocus To measure pixel statistics you may use MSCEXAMINE or MSCSTAT a Mosaic version of IMSTAT MSCSTAT runs IMSTAT or each of the selected extensions in a list of Mosaic files To restrict the measurement to a region you image sections that apply to all of the selected extensions For example to measure statistics at the center of a set of observations the command would be something like cl gt mscstat fits 900 1200 2000 2300 There was some discussion earlier concerning use of generic image tasks with the NOAO Mosaic data The tasks IMHEADER and HSELE
19. eduzzcollector NOCS mosaicidhs 01 4m kpno noao eduttcollector Bang mosaicldhs 01 4m kpno noao eduttmosdca mosaicldhs 01 4m kpno noao eduttsmemgr mosaicidhs 01 4m kpno noao edutipxf mosaicidhs 01 4m kpno noao edustpymd3 mosaicldhs 01 4m kpno noao eduzzpvmgs mosaici 4m kpno noao edu semccd 15174 DISPLAY gt localhost 10 0 Files mosaici 4m kpno noao eduz home observer ngui and mosaicidhs 01 4m kpno noao eduz home observer ngui are synchronized observer mosaicl 4m exec N RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING RUNNING NOCS xterm 1 2a ve 4816 4819 4855 5356 DISPLAY gt localhost 10 0 4856 4863 4972 4973 DISPLAY gt localhost 10 0 4857 4861 4968 3 DISPLAY gt localhost 10 0 4858 4864 4970 3 DISPLAY gt localhost 10 0 7781 DISPLAY gt localhost 10 0 7861 7872 9859 9860 9861 9862 DISPLAY gt localhost 10 0 8096 8112 8113 8114 DISPLAY gt localhost 10 0 8301 DISPLAY gt localhost 10 0 8756 DISPLAY gt localhost 10 0 9244 DISPLAY gt localhost 10 0 9824 DISPLAY gt localhost 10 0 11280 DISPLAY gt localhost 10 0 4
20. effect can be measured and calibrated out but it can also be avoided with longer exposures since the shutter error is a constant offset in time Relative 5 Below are ratios of new relative QE vs old relative QE and expected electrons second for 20 magnitude start The SDSS z band is estimated based on the R and I band values and the expected QE curve of the new e2v CCDs old relative QE 20 mag __ 123 32252 0976 7 35468 __ Table 12 New relative QEs 67 8 0 APPENDIX D Flat Feld Exposures Typical Dome flat field exposure times for each filter are given in Table 13 These exposures should produce pictures having 125 000 150 000 ADU per pixel to stay within the linear regime Note that each ADU represents 1 electron so there is plenty of signal with these recommendations To minimize thinking at the telescope we tried to use the maximum voltage settings when possible 4 m 53V 0 9 m 100 Note that these exposure times are for the normal gain setting For logain mode the exposure times are approximately one half the listed exposure time Flat Field Lamp Settings and Exposure Times Lamp Setting Exposure Time Lamp Setting Exposure Time B 5 _ 60s Low 100 6068 R 5 58 100 1 I Low53V 555 100 _ 15 Halpha 8 High53V 22 100 _ 2 om High53V 95 High 100 18 29 100 77 go Low53V _ 38s 100 25
21. eie 18 FIGURE 3 THE MOSAIC T T COMPUTER arenen EE 18 FIGURE 14 THE BROAD BAND FILTER SET INCLUDING THE WHITE FILTER sccoccceccceccccscucccuccucseuceuceeusecseuseuuseecsenseueees 22 FIGURE 15 THE SDSS Z FILTERS ALONG WITH THE WASHINGTON AND 22 FIGURE 16 THE CURRENT SET OF HA PLUS REDSHIFTED FILTERS 1 1 23 FIGURE 17 THE BLUE WOLF RAYET FILTERS FOR AND CONTINUUM 4750 00 00 23 FIGURE 18 THE ON BAND AND OFF BAND FILTER PLUS 1 1 1 010 06 6 24 FIGURE 19 THE V BAND FILTER INSTALLED IN THE FILTER TRACK 1 24 FIGURE 20 SCHEMATIC DRAWING OF THE LAYOUT OF THE TV CONTROL PANELS AT THE 9 26 FIGURE 21 eap ARES Usu QU a eU NU ED tars 26 FIGURE 22 THE 0 9 M CORRECTOR OPTICAL EA 27 FIGURE 23 THEADO GUI 29 FIGURE 24 THE MOSAIC DESKTOP TO LAUNCH THE MAIN MOSAIC 32 FIGURE
22. is a way to take data and ignore the filter position In the NGUI deselect the Filter Commands checkbox Note that if this is unchecked scripts will not execute a filter change 80
23. m or emerald at the 0 9 m we list the full compliment of computers for completeness All of the computers listed below are at the 4 m however there is an identical set of computers at the 0 9 m that are the same except for the naming convention 36 replaces 4m mayall 2 or mayall 3 a Mac mini computer in the 4 m control room from which all programs are launched emerald a Linux computer in the 0 9 m control room from which all programs are launched mosaic1 4m the main computer that runs the NOCS and co ordinates the data acquisition 1 4 the MONSOON pixel acquisition node PAN computer Presently called pan a because upon upgrading to Torrent controllers there will be a pan b mosaicidhs 01 4m the main data handling system machine that ingests data from the PAN and performs various data management tasks and produces the final FITS image on disk This image is transferred back to mosaic1 4m Presently called dhs 01 because upon upgrading to Torrent controllers there will be a dhs 02 mosaicispare 4m a spare machine that includes a spare systran card This system can be reconfigured in minutes to replace any of the other systems that have failed 3 2 Starting up the Software The NOCS software runs on the computer mosaic1 4m at 4 meter or mosaic1 36 at 0 9 m but is displayed on the computer mayall 2 at the 4 m or emerald at the 0 9 m Mayall 2 is a Mac mini computer wit
24. motion of the shutter blades is along columns There is a shutter timing error that is very constant for exposure times greater than 0 2 seconds The shutter corrections are shown in Table 7 The user interface limits the exposure time to a minimum of 0 2 seconds to ensure good linearity The maximum exposure time allowed is 3600 seconds Field Location Exposure Time Correction East edge 0 030 seconds Center 0 023 seconds Table 7 Exposure time correction for the shutter timing error 19 2 5 The filter track holds 14 filters For each filter position there is a filter for the CCD field and two separate filters for the two TV fields Separate filters are used so that a narrow bandpass science filter does not constrain the observer to find very bright guide stars Normally one would use clear BK7 filters for the TV but one can use a red filter to minimize moonlight or match the science filter more accurately One might want to match the science filter at least approximately to minimize a guider drift Even at the 4 m residuals after the correction from the ADC are of order 0 1 0 2 arcsec This and all filter decisions must be made ahead of time as the filters can only be changed during the day by a qualified observing technician Adapters exist to allow the use of 4 inch square 1 adaptor and 2 inch square 2 adaptors At the 0 9 m f 7 5 these 4 inch filters illuminate approximately 6K x 6K pixe
25. multiple nohs processes running so be careful not to type the nocs start nohs unless it has indeed quit Typing nocs stop nohs will kill all instances of the nohs process that are running 11 4 I can t start the NOCS software If you tried clicking on the Start button on the Main Mosaic GUI and nothing happens the software may be in a bad state This command to start up the NOCS software can also be executed from an xterm window that is logged in to the mosaic1 4m or mosaic1 36 computer Executing this from the command line will allow you to see if there are any errors or failures upon startup To startup the software type nocs start all The software first checks to be sure there is other instance of itself currently running if there is then it will not start It s possible that it could be running on a different screen or that someone is running it remotely The software may also not have been shutdown cleanly leaving some processes still running When typing the above command and you get back an error claiming the software is already running you can double check what is and isn t running by typing nocs status all see Figure 46 above for the results If some processes are stopped and some are running it s likely that the software wasn t shut down cleanly You can stop and then restart the software by typing nocs stop all in the xterm window logged in to mosaic1 4m or mosaic1 36 waiting approxim
26. prisms Be assured the prisms are moved before the shutter opens it is just the updating of the GUI that is lower priority for the CPU 11 2 Loss of header information Occasionally header information will stop being populated to all extensions Sometimes this appears in the real time display as only 1 extension being displayed actually it is all 16 extensions displayed on top of each other To remedy this stop and restart the NOCS software 1 Click Stop in the Main Mosaic GUI 2 Wait for Ready at the top of the Main Mosaic GUI 3 Click Start in the Main Mosaic GUI Note this problem seems to be fixed now Nov 2 2011 11 3 When do I type nocs start nohs When the NOCS system is started all necessary programs should be launched To see if all programs are up and ready type nocs status all in an xterm logged in to mosaic1 4m or mosaic1 36 You should see a list of all processes followed by RUNNING see Figure 46 You should see that the nohs is running Upon the first execution of a script the nohs process usually dies for an unknown reason and your script is aborted with the following error message FAILURE TASK nohs ACTION nohs_newobs ARGS headers You can see if the nohs process is still running by typing nocs status all again This time it should say stopped If it indeed has died it can easily be restarted at any 78 time by typing nocs start nohs Note it is possible to have
27. telescope Dark frames may be required but usually not It is safe practice to obtain darks with exposures Similar to your science images Dome flats provide basic flattening of the frames to 1 or so but night sky flats or illumination corrections likely are required to produce images that can be stacked without introducing obvious artifacts Using night sky flats we can flatten images to 0 1 Twilight flats do not appear to work quite as well as dark sky flats due to regions of variable thinning that cause slightly wavelength dependent features but they work better than dome flats Finally good astrometry is required to register and stack the Mosaic images We have derived solutions for most filters but the scale varies slightly with color so you may want to image an astrometric field if you are using your own filters Our experience indicates that the array is geometrically very stable 4 7 Basic Reductions Almost all of the basic image reduction is done under the IRAF MSCRED package Before you get started you should be aware that the Mosaic multi extension FITS data format means that you will have to be careful to stick to the routines in MSCRED that can handle this format In many cases useful routines from CCDRED have been rewritten with the same name to be available in the MSCRED package IRAF routines in other packages can be used on one CCD ata time either in scripts or the command line but will not work directly on an entire mos
28. the image would have the damaging effect of causing the photometric zeropoint to vary from center to field corners by 8 Note that this effect is different from vignetting where the flux actually delivered to the image margins is less than that at the center an effect that is corrected by the flat field In practice the photometric effect of the variable pixel scale can be ignored provided that the reduced images will be part of a dither sequence to be stacked later on As discussed in the next section prior to stacking the images they first must be re gridded to a tangent plane projection which has pixels of essentially constant angular scale This is done with the MSCIMAGE task which re grids the pixels and has a flux conservation option that can scale the pixels photometrically by the associated area change If this function is disabled then improperly flattened images will have a uniform zero point restored with this option turned off In short the flat field already adjusted if inappropriately for the different pixel sizes 50 MSCIMAGE would then do no further adjustment Stars would be too bright in the corners of the flattened images but after re gridding their total fluxes would be scaled down to the appropriate values If the Mosaic images are to be analyzed individually however as might be done for standard star fields then after the flat field reductions are complete the differential scale effects must be restored
29. there is a focus offset A list of all available filters and their properties can be found at http www noao edu kpno mosaic filters Note that for the post processing command to display the correct on the fly flat the official filter name must be specified in the correct parameter set The official names can be found at 20 http mosaic filters filter names Central FWHM Central FWHM e s T Wave Wave ________ 55612 795 357 646 351 3577 6471 2 O 63 4260 390 330 960 390 16 BK7 884 5370 940 340 5370 940 15 610 1 BK7 939 8220 1930 225 8220 1930 9 7 943 6569 480 6575 80 __ 7 912 6611 81 6615 81 __ H 8 _____ 7 895 6650 81 6656 81 12 7 861 692 81 6695 81 __ 6 BK 7 907 6730 6736 80 50552 7 902 48131 137 4813 1537 50557 ___ 7 918 6287 1468 6287 1468 5055 ___ 7 946 7732 148 7732 1548 50552 7 948 9400 2000 7 9400 2000 2 ___ 7 752 5021 5 5027 53 0 29 2 BK 7 905 535 21 __ 5305 2411 White ____ 7 972 5600 6800 7 5600 6800 __ WashM _____ 38 871 5100 1140 5100 1140 WashC 58612 754 3860 1034 380 104 __ DDO51 BK7 851 512 11 5132 161 7 684 4653 5
30. window EE X DARK Observation s DARK30min OBSERVATION CONFIGURATION 1x1 2 OK Cancel JEE Figure 58 NGUI Dark configuration window 73 ZERO Observation s Figure 59 NGUI Zero configuration window X FOCUS 8 3 FOCUSR ew ______ Figure 60 NGUI Focus configuration window 74 NOCS xterm 1 DITSCMD_24d9snohstnohsDramaNewObs DONE SUCCESS 1 TASK nohs ACTION nohs_newobs BRGS headers DITSCMD_24datnmslinms DramaInit DONE DITSCHD 24dbznmslznmslDramaGpxSetAVPz DONE SUCCESS 1 TASK nmsl ACTION nmsl_gpxSetAYP ARGS exp1D 2455493 0298305680043995 DITSCHD 24dcznmslznmslDramalInitz DONE DITSCHD 24dd nmslznmslDramaGpxbetState DONE OK SUCCESS 1 TASK nmsl ACTION nmsl_gpxGetState ARGS IGNORE DITSCHD 24ffznmslznmslDramaInitz DONE DITSCHD 2503 exit status 2DITS F SIGINT DITS Exited via exit handler with signal SIGINT lt lt ABANDONED gt gt home observer exec standards_d sh at line 101 executing ditscmd nmsl nmsl apxStartExp If you were INTEGRATING you should do the following If you were NOT integrating you re probably OK to continue anyway 20080312 observer mosaici 4m 4 Figure 61 Procedure displayed an xterm window when script is aborted Be sure to follow the on screen instructions displayed 10 APPENDIX GO
31. 0 t i E 40 4 T i z Lo e PU 20 d 7 des F H ef LLLI 2111111 9450 8550 9650 6750 9850 Wavelength Figure 16 The current set of Ha plus redshifted filters Note that 16 serves SII filter Transmission 96 4550 4600 4550 4700 4750 4800 4850 Wavelength Figure 17 The blue Wolf Rayet filters for and a continuum 4750 23 100 90 80 70 Transmssion 4900 5000 5100 5200 5300 5400 5500 Wavelength Figure 18 The on band and off band filter plus DDO51 V band Science Filter TY Filter TV Filter Figure 19 The V band filter installed in the filter track The 2 TV guider filters are visible to the lower left and upper right of the science filter 24 2 7 Operation of the Guider TVs Guiding with the Mosaic is accomplished using one of two TV cameras on the north and south sides of the science field These are intensified fiber optically coupled CCD cameras ICCDs so they can be damaged if exposed to bright light The video signal from the selected TV camera is fed to the guider system The field of view of each camera is about 2 2 arcmin on a side at the 4 m and about 5 arcmin on a side at the 0 9 m The field of view of the TVs is fixed with respect to the science f
32. 2 4660 50 WRHell ___ 7 733 460 51 4695 49 __ 475 7 788 4750 51 4755 49 Table 8 Some of currently available filters and approximate count rates for a 20 mag star See Figures 14 through 18 for plots of the current filter transmission curves ASCII Tables that describe the transmissions are available on the Mosaic Web Pages The U band CUSO filter is based on the same formulation as our 4 filter set liquid CuSO UG 1 Because containment of the liquid requires a thickness around the edge that exceeds the nominal Mosaic dead zone some vignetting is present At the 4 m the vignetting introduces a 2096 loss of light at the edge but recovers to zero loss at 200 pixels from the edge 21 100 90 24 9 6 949 0 00 0 0660 0900 060006 0 Qe OHSS 09 46 o0 bs o9 9 4 4 80 70 50 50 40 Transmission 30 20 10 OAL ETETETT 10 3000 4000 5000 6000 7000 8000 9000 10000 Waveength A Figure 14 The broad band filter set including the White filter 100 90 80 70 60 50 Transmission 40 30 20 10 10 3000 4000 5000 5000 1000 8000 9000 10000 Wavelength Figure 15 The SDSS 9 z filters along with the Washington C and M M is the smooth curve slightly redder than 9 22 e sje 90 p 3
33. 276 4285 4503 4506 4509 4512 4515 4518 DISPLAY gt localhost 10 0 4373 DISPLAY gt localhost 10 0 4317 DISPLAY gt localhost 10 0 4522 DISPLAY gt localhost 10 0 4501 DISPLAY gt localhost 10 0 4805 DISPLAY gt localhost 10 0 4943 DISPLAY gt localhost 10 0 5901 DISPLAY gt localhost 10 0 4980 DISPLAY gt localhost 10 0 5226 DISPLAY gt localhost 10 0 4022 DISPLAY gt localhost 10 0 4133 DISPLAY gt localhost 10 0 11342 Figure 46 NOCS status all when NOCS ts up and running File ee Data Handling System Supervisor Help Quit Process Status Shared Cache Real Tine Display Paths 8 Files Gu Show Activity Verbose Clean SHC Page Usage nosaicldhs 01 nosaicldhs 01 Disk Usage 53 OU Connect Status Exp Status Figure 47 DHS Process Status window 69 I Data Handling Sustem Supervisor File Help Quit Process Status Shared Cache Real Tine Display Paths amp Files Paths Ports 8 Hodes inage Zdata 2 observer 20101023 Zdata 2 observer 20101023 Zdhs lib ktn tcl Zdhs lib sysproc dhs lib postproc SHC Page Usage nosaicldhs 01 nosaicldhs 01 Disk Usage 53 I NU Connect Status Exp Status Figure 48 DHS Paths amp Files window
34. 4meter acorn 2 4 meter VDU 4 56 05 11 05 2010 LST 0 26 59 Mosaic 1 1 Configuration Monitor Shutter ready guide 23 24 10 47 60 57 31 0 2000 0 Ambient 7 15 8 HA 1 02 16 ZD 30 79AM 1 164 Filter VR Bernstein k1040 OFFSET 0 0 0 0 tsi 5 0 00 0 0 Dewar 2 1773 CCD 1 107 6 4 34 5 FOCUS 9217 DOME 342 5 PARAL ERR 1 4 INST MOSAIC FIELD CCD ee FILTER 12 ADCI 0 1 10 ADC2 0 STV 1 90 Power 5 39 9 ADC 1 Angle 0 00 ADC 2 Angle 0 00 Pedestal Focus 921700 microns 0 View Messages Apply Update Gear T Using protocol version 3 Thu Nov 4 17 28 15 2010 TXInage Using default colormap and visual TrueColor depth 24 CConn Using pixel format depth 6 8bpp rgb222 CConn Using ZRLE encoding CConn Throughput 20000 kbit s changing to hextile encoding Conn Throughput 20000 kbit s changing to fu colour CConr Using pixel format depth 24 32bpp little endian rgbB88 CConn Using hextile encoding Figure 29 The Mayall 2 top monitor with necessary windows shown the VDU MCCD GUI and Truss Temp 34 The main windows required to observe with Mosaic 1 1 are there are 7 of them 1 NMSL Mosaic 1 1 the main instrument status window with countdown clock detector information gain selection and exposure control pause abort etc F7 78 78 Fil
35. 8 572 2037 2041 25 582 3 582 6 04 567 557 561 2056 2060 25 5823 583 5 445 572 496 500 2072 2076 25 582 8 582 4 884 573 411 415 2078 2082 25 580 3 581 4 91 571 408 412 2078 2082 25 581 1 58 5 224 570 1398 402 2073 20771 25 581 1 580 8 575 390 394 2042 2046 25 582 3 583 5 222 571 281 285 2022 2037 25 581 8 582 4 29 574 ecl mi Switch OFF email alerts for temperature events 2 Figure 32 The VNC DHS window where images are displayed 4 MCCD configuration GUI a graphical representation of the Mosaic light path with temperatures displayed Mosaic 1 1 Configuration Monitor Shutter ready dark Ambient 7 10 5 Filter Harris 1004 0 82 2 168 6 4 28 7 Focus 8364 jPower 5 435 9 Figure 33 A Mosaic legacy GUI displaying temperatures 36 5 Mosaic 1 1 Imager the Mosaic GUI to select filters and change telescope focus 000 X Mosaic 1 1 Imager back u Filter i 7 03 Shutter Guide Open ready None Dark Guide Restore Camera Focus 0 82 Camera 5 Focus 2 30 0 8 D 2 3 STOP ror H BS ADC 1 Angle 32 07 ADC 2 Angle 21 2 10 Pedestal Focus 836400 microns gef View Messages Apply Update Clear I ha hal6 Usage hints appear here 4 Figure 34 A Mosaic legacy GUI enabling fi
36. ATION WINDOW cccceccececcececcecuccucncceceenscuseceueuceeeeceeeeeeaeeeeeeeeseseeseeeeseeeesess 72 FIGURE 53 NGUI MOSDITHER CONFIGURATION WINDOW sccececcececcecnccecuccececuccusuccesuceeeeseeeeeeaeeeeeeeecseeeseeeseseesess 72 FIGURE 54 NGUI OBJECT CONFIGURATION WINDOW EN 72 FIGURE 55 NGUI TFLAT CONFIGURATIONS WINDOW sceccecceccecececcuccuccecscuseusuceuseuseuseeeuseuseusseuseueseeseuseuseeeaseneess 72 FIGURE 56 NGUI DFLAT CONFIGURATION WINDOW seen us 73 FIGURE 57 NGUI TEST CONFIGURATION WINDOW escis obe 73 FIGURE 58 NGUI DARK CONFIGURATION WINDOW cscececcecacceccsceccscecavcscscarsecersacessacesaseecassesavaceeeastesastecarsecarsecara 73 FIGURE 59 NGUI ZERO CONFIGURATION WINDOW hee hehehe she eese esse inse se ense see esse nnns 74 FIGURE 60 NGUI FOCUS CONFIGURATION WINDOW cececcececcececcuceccucuccucuenececuecuseceeeeseeeeceeeeeeaeeeeeeeeseeeseeeeseeesess 74 FIGURE 61 PROCEDURE DISPLAYED IN AN XTERM WINDOW WHEN A SCRIPT IS ABORTED 1 75 FIGURE G2 SAT URAGED assesses RE 77 1 0 Mosaic 1 1 Overview At Least Read This The Mosaic 1 1 imager is a wide field imaging camera built for use at the 4 meter and WIYN 0 9 meter tele
37. CT fall into this category The two important points to keep in mind are that you must specify either an extension name or the extension position and that the headers of an extension are the combination of the global header and the extension headers Often one does not need to list all the headers for all the extensions The image title and many keywords of interest are common to all the extensions Thus one of the following commands will be sufficient to get header information about an exposure or set of exposures cl imhead obj 1 l Title listing cl gt imhead obj123 1 1 page Paged long listing cl hselect obj 1 1 filter exptime obstime yes If you need to list header information from all the extensions then you need to take the additional step of creating an file For example to get the default read noise and gain values for each CCD cl gt imextensions obj123 gt list123 cl hselect list123 I rdnoise gain yes Rather than create list you can use MSCCMD cl msccmd hselect input I rdnoise gain yes The CCDLIST task in the MSCRED package is specialized for the Mosaic data It provides a compact description of the name title pixel type filter amplifier and processing flags By default it lists all the extensions but the extname parameter may be used to select a particular extension Because all extensions should generally be at the same state of reduction it may be desirable to list only the first extensi
38. FOR THE PRIMARY MIRROR TO SETTLE DURING A MOSDITHER ONE EE 80 11 8 TAKE AN IMAGE BECAUSE THE FILTER TRACK WON T LOCK INTO PLACE 80 INDEX OF TABLES TABLE 1 GENERAL Mosaic ITCHARACTERISTICS eene essa 5 TABLE 2 OBSERVING MODES AND MODE SPECIFIC 5 5 1 hehehe eene eese esee 5 TABLE 3 KINO 4 IVIETER REESEN epus 6 TABEE EE E ee 6 TABLE 5 NORMAL CCD OPERATING CHARACTERISTICS ccccecccecccescccceuccucccuseccsuucecuseceseuceceeeuseeseueeeuseecsuneeeee 15 TABLE 6 LOGAIN CCD OPERATING CHARACTERISTIS ccccseccscccuccccccccseuceucccuceucseucceusecesuuceeseuuseeuseuseeuseesuneeuees 15 TABLE 7 EXPOSURE TIME CORRECTION FOR THE SHUTTER TIMING ERROR sene 19 TABLE 8 SOME OF THE CURRENTLY AVAILABLE FILTERS AND APPROXIMATE COUNT 21 TABLE 9 DITHER FILES DEFINED DEEN 48 TABLE 0 THE DEFAULT FILL GAP DITHER OFFSET EE 49 TABLE TI THE DEFAULT 8Q DITHER OFFSETS 50 TABLE 12 NEW REEATIVE 50 TABLE 13 APPROXIMATE DOME FLAT SETTINGS AND EXPOSURE TIME
39. LIBRATION DATA TO OBTAIN AT THE 5 59 2 GH 31D BY Ge EE 59 4 8 THE VARIABLE PIXEL SCALE AND ZERO POINT UNIPORMITN eere eene nnne 60 STACKING MOSAICIMAGES 61 4 10 A SIMPLIFIED SUMMARY OF THE PROCESSING STEPS cccccsscccesececeececeseceueceuseseueeseueuceuens 63 5 0 APPENDIX A MISCELLANEOUS SOFTWARE COMMANDS 65 7 0 APPENDIX ISSUES ABOUT 67 8 0 APPENDIX D FLAT FIELD 5 65 68 10 APPENDIX GOT CHAS sisesissscccssssinndscscsieessestiivexsunesscnsvasecvesvessssovieveaunsveseowasedasenaiesstexees 76 11 APPENDIX 5 1001 78 11 1 THE ADC DOES NOT SEEM REACTING FAST ENOUGH 78 11 2 LOSS OP HEADER INFORWIA TION EE 78 113 WHEN DOITYPE NOGS START NOUS 2 a ae 78 11 54 THEINOCS SOFTWARE idu Eo ae ima ts 79 11 5 THE SHUTTER RETURNS THE DARK POSITION AFTER EVERY EXPOSURE 79 11 6 EXECUTED A SCRIPT BUT NOTHING HAPPENED ccsssccccccesecceceesseceseesssesessuseseeeas 79 11 7 IT TAKES TOO LONG
40. Mosaic 1 1 imager on the Mayall 4 m The 8 CCDs are divided up into 16 extensions that are labeled in the figure as the numbers 5 The Mosaic cameras require large 5 75 inch filters We can provide an adapter for 4 inch filters but using them makes poor use of the Mosaic wide field of view 1 7 Supplemental Information Other manuals and Web pages to look at Other useful information regarding the use of the Mosaics CCDs and observing and reduction software can be found at the NOAO Mosaic Camera web pages http www noao edu noao mosaic Information of what calibration images are needed can be found in Direct Imaging Manual http www noao edu kpno manuals dim dim html NOAO KPNO Mosaic Web Page http www noao edu kpno mosaic mosaic html WIYN 0 9 m User s Manual http www noao edu 0 9m manual html Buell Jannuzi s Reduction Guide http www noao edu noao noaodeep ReductionOpt frames html Various Publications SPIE ADASS A New Image Acquisition System for the Kitt Peak National Observatory Mosaic 1 Imager http ww noao edu kpno mosaic SPIE7735 117 pdf A New Wide Field Corrector for the Kitt Peak Mayall 4 m Jacoby 1998 SPIE 3355 721 http www noao edu noao meetings spie98 10 2 0 The Mosaic Hardware 2 1 The Mosaic 1 1 CCDs The Mosaic 1 1 Imager features eight e2v Technologies CCDs that are 2048 serial or pixels row x 4096 parallel or pixels column 15 um pixel CCDs arranged
41. NFO gt name nquiLocals 0BS C 7 VAL element 0BS_C_7_VAL op w dhsz MetaData mdConfigTcl metaTupe 2 numFields nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_9 VAL element 0BS C 9 VAL dhsi Metalata mdConfigTcl fieldSize 0 32 dataTupe 0 1 nquiTraceSeq lt INFO gt name nquiLocals OBS C 10 VAL element 0BS C 10 VAL op dhsiiMetalata mdConfigTcl fieldSize 1 32 dataTupe 1 nguiTraceSeq lt INFO gt name nquiLocals D0BS C 12 VAL element 0BS C 12 VAL dhsi MHetalata mdConfigTcl fieldSize 2 64 dataTupe 2 nguiSetExecOpen lt INFO gt opened file home observer exec O3test sh lt H gt dhsSendMetaData starting bservation Number 1 2495505 906468 stat 0 istat 0 nguiSetObs lt OBJECT gt Writing observation 1 1 1 1 with DPOS ignore 05 XM dhsSendMetalata send Ox9af3de0 size 120 stat 0 istat 0 nguiSetExecClose lt INFO gt wrote script home observer exec O3test sh XM dhsSendMetalata sent OxSaf3dc size 120 stat 120 istat 0 ConnMon XM dhsSendMetaData send metadata size 18175 stat 0 istat 0 P shot XH dhsSendMetaDatat sent metadata size 18176 stat 18176 istat 0 53 19 PM lt M gt dhsSendMetaData send mdConfig Oxbfa646a0 size 32776 stat 0 istat 0 N Telescope Commands Filter Commands gt dhsSendNetaData sent mdConfig Oxbfa646a0 size 32776 stat 32776 istat 0 dhsi Metalata lstat 0 DI
42. PERATURE PROGRAM 38 FIGURE 39 7 HE AUTOLOG CONTROL PANEL ES s 39 FIGURE 40 THE NGUI WITH BUTTONS AT THE BOTTOM FOR SCRIPT 2 39 FIGURE 41 THE ZERO SCRIPT CONFIGURATIONS GUI USED TO CREATE SCRIPTS FOR TAKING BIASES 40 FIGURE 4 2 THE SETIPROJECTOUT TES Ed UL Mp I P UE 44 FIGURE 43 THE PROCEDURE FOR RECOVERING FROM AN ABORTED SCRIPT 47 FIGURE 44 AN ON SKY MAP OF A MOSGRIP DITHER WHICH USED A 2 X 2 RADEC GRID WHERE EACH POINT USED A FILLGAP 5 POINT DITHE L 49 FIGURE 45 A PLOT SHOWING THE DIFFERENTIAL PRISMATIC DISTORTION DUE TO ATMOSPHERIC REFRACTION OVER THE EXTENT OF THE MOSAICI LO EE 66 FIGURE 46 NOCS STATUS ALL WHEN NOCS IS UP AND RUNNING 69 FIGURE 4 7 DHS PROCESS STATUS WINDOW ees 69 FIGURE 48 DHS PATHS EECHELEN VE DRE RAUS 70 FIGURE 49 DHS SHARED MEMORY CACHE WINDOW sceccececcececcecnccucuccecncuscecnscusnccesnceeeeseeeeeeeceeeeeeeseeeseeeeseseesea 70 FIGURE 50 DAS REALTIME DISPLAY WINDOW 71 FIGURE 51 INIVISE OPTIONS EE 71 FIGURE 52 NGUI MOSGRID CONFIGUR
43. Reset GPX Commands rmocouple temp1 106 699997 S ocal Plate Temperature too LOW Temp 106 700 Reset GWC Commands rmocouple 1 106 400002 nmsli ocal Plate Temperature too LOW 106 400 rmocouple temp1 106 699997 nmsli Enable Temperature Control ocal Plate Temperature too LOW Temp 106 700 nmsl Enable ADC Control rmocouple templ 106 400002 rmsli ZUM Plate Temperature too LOW 106 406 nt adcready 1 nnsli Hide Text Window nt adcready 1 nt 1 rmslGwcHandleValue lt RECV gt mse arint adcready 1 nmslGwcHandleValue RECV mse thermocouple temp1 106 699997 rmslGwcHandleValue URGENT CCD Focal Plate Temperature too LOW Temp 106 700 nmslGwcHandleValue RECV mse thermocouple temp1 106 400002 nmslGwcHandleValue URGENT CCD Focal Plate Temperature too LOW 106 406 rnmslGwcHandleValue RECV mse thermocouple templ 106 699997 rnmslGwcHandleValue URGENT CCD Focal Plate Temperature too LOW Temp 106 700 Aan Temperature 10670 Am gwc Kpno noao edu 2347 Finished script home observer exec DARK30min sh H Sat Oct 23 11 20 04 PM MST 2010 New Integration Time s Status DONE Mode normal 00 7 OO Read Noise 5 0 Binning ars Read Out 5 19 Set Mode ADC Ready 1 ccD Temp
44. S cccsceecceceeceuccuccccccuscuceuseuceuseuseuseuseesseuseuseuseueeesen 67 INDEX OF FIGURES FIGURE 1 THE DISPLAY ORIENTATION OF THE 16 SECTIONS OF THE MOSAIC 1 1 IMAGER ON THE MAYALL 4 M 10 FIGURE 2 ORIENTATION AND LAYOUT OF THE IN THE IVIOSAIC FOCAL PLANE AT THE KPNO 4 METER TELESCOPE 11 FIGURE 3 QUANTUM EFFICIENCY OF E2V CCDS IN THE MOSAIC 1 1 1 00 00000006 enne senes 12 FIGURE 4 TYPICAL BIAS IMAGE SHOWING THE AMPLIFIER BOUNEN 12 FIGURE 5 TYPICAL FLAT FIELD IMAGE R BAND ss stie toda _ _ _ _ _ 13 FIGURE 6 VIGNETTING AS SEEN ON THE RIGHT EDGE OF CHIP 4 ccccccccceceuccuccuscuseuseuceusceuscuceuseuceueeuseuseueeuseuseuseuseseeses 13 FIGURE 7 HIGHLY STRETCHED I BAND IMAGE SHOWING THE FRINGE PATTERN cscceeceeceeccccccescuceuccuceuseucsusssseuseuseuseuseuses 14 FIGURE 8 LINE PLOT OF AN I BAND IMAGE SHOWING FRINGING cccecccccceccuccuccuceuseuceucsccscuseuseuseuseuseuseeseesseuseeseuseseeses 14 FIGURE 9 IMAGE OF FULL WELL SATURATED STARS SHOWING THE EFFECTS OF CROSSTALK BETWEEN CCD OUTPUTS AND THE TRAILING GHOST ANOMALY 16 FIGURE 10 THE MOSAIC 1 1 INSTRUMENT BEING VACUUM PUMPED ceeceeccececccuccuceucsecscuseuseucsuceuseuseuseuseuseusenseuseeses 17 FIGURE 11 THE MCCD GRAPHICAL USER INTERFACE 17 FIGURE 12 THE MONSOON DETECTOR HEAD ELECTRONICS DHE BOX WITH THE ACCESS COVER REMOVED
45. TCHAS Below is a list of known bugs and features Most will be fixed soon 1 Never abort a dither script It crashes the system 2 Don t do several abort exposures in a row This will also crash the system Instead use Ctrl C in the xterm window where the script was executed to quit out of the script 3 If you edit and save the currently executed script it will kill the current script and exposure 4 Right now the maximum offset that can be done 15 45arcmin 5 The minimum exposure time is 0 2 seconds The maximum exposure time is 3600 seconds 6 The countdown timer and shutter get out of sync on longer exposures Not to worry the exposure will be of the correct length It is a problem with the synchronization with the displayed countdown timer 7 Don t change the gain mode during an integration or readout 8 Sometimes the DHS does not keep up with the images being taken and there seems to be a backlog of images that have been taken but not displayed or saved to disk Sometimes it seems to help move these images through the DHS if you select Update Status and Process Next on the Shared Memory Cache screen within the DHS 9 Do not open and use multiple script configurations simultaneously This could interfere with the current script being run and will certainly cause havoc with any scripts you are trying to write 10 Below is a snapshot of an image that is saturated for reference 76 NOAO IRAF XImtoo
46. TSCHD 5ai nohs nohsDramaNew bs DONE ldhs 01 4m kpno no Focus MosDither SUCCESS TASK nohs ACTION nohs_newobs RRGS headers DITSCHD 5a2 nmslinmslramalnit DONE TwilightFlat Object MosGrid DITSCH nmslinmsllramaGpxSetRVP DONE 5 1 TASK nms ACTION nmsl_gpxSetAVP ARGS exp1D 2455505 9064679313451052 e DITSCHD 5ad nmslznmsllramalnitz DONE Refresh Filter s Set Project Exit DITSCHD 5a5 nmslnmslDramaGpxGetState DONE OK SUCCESS 1 T SK nmsl ACTION nmsl_gpxGetState ARGS IGNORE NGUI v20101102 C 2010 AURA Inc Contact Philip Daly pnd noao edu ses nc DONE x aS Ph gt y gt NGUI the Mosaic GUI 33 The right hand monitor should look similar to this X KPNO 4meter Autolog Control Panel X VNC 1 4 1 monsoon File Help S EE Image directory data2 observer 20101104 z super m RAWDIR set to data2 observer 20101104 File Help Quit NOAOZIRAF XImtool Version 1 1a E Process Status Shared Cache Real Time Display Paths 8 Files un E conum Logging Options d Print log sheets automatically Instrument Mosaic 1 10 10 38 R Marzke 9 20 03 D Mills DetNane Telescope UT Date Nov 4 2010 Image filename Object
47. The correction process is simple The scale at any 60 point in Mosaic is already known from astrometry so could just calculate and multiply by a correction surface The final image would appear to have a variable sky level but would be photometrically uniform We also note that performing surface photometry on Mosaic images with their native sampling can cause biased results unless care is taken to track the changes in the pixel scale 4 9 Stacking Mosaic Images In many ways the real work of reducing Mosaic data comes when preparing to stack the images to make a final deep image free from gaps and artifacts Not only is there a premium on having well flattened data to begin with but one must also understand the relative photometric and sky level variations among the images ina dither set At any point in the final stacked image different frames will be making differing contributions Any differences in scaling will produce noticeable artifacts in the final sky background or zeropoint In practice we have found that the stacking works beautifully with data obtained under clear conditions and with no bright stars near the fields on the other hand we have found that simple reduction strategies produce very poorly stacked images if the shape of the sky over the field or scattered light contributions varied over the course of a dither sequence or over the course of the night used to define the sky flat The first step
48. Version 4 3 2011 Revision Heidi Schweiker Steve Howell and Dave Sawyer With contributions from Buell Jannuzi Phil Daly George Jacoby Taft Armandroff Todd Boroson Jim DeVeny Steve Heathcote Tod Lauer Bob Marshall Phil Massey Rich Reed Frank Valdes David Vaughnn A raw image of the Moon courtesy of the commissioning team as observed with the KPNO 4 m telescope and Mosaic 1 1 Send comments on the manual to Heidi Schweiker or Steve Howell TABLE OF CONTENTS 1 0 MOSAIC 1 1 OVERVIEW AT LEAST READ THIS 5 Ib GENERAL EE e Ne KEE 5 1 2 MAYALL 4 METER PARAMETERS 6 1 3 EXPECTED WIYN 0 9 METER FORMERLY KPNO 0 9 6 14 ALL OF THE COMMANDS THAT LIKELY nenne 7 1 5 WHAT S CHANGED WITH 5 1 1 00 0 216 66 6 ne nennen 8 1 6 INSTRUMENT AND DATA OVERVIEW Eed Loos eet uto e te 9 1 7 SUPPLEMENTAL INFORMATION 10 2 0 ENEE 11 ZA THE MOSAIC LI CC S 11 dnd ct 16 2 9 THE DATAACOUISIFION SY STEM EE 17 24
49. View Go Window Help 2 4 Thu 21 52 22 4meter Q 2 X NMSL Mosaic 1 1 Mosa 1 1 File Options Mosaic Menu MOSAIC Ready Thu Nov 04 09 45 19 PM MST 2010 Integration timer 414 0 900 0 4m gwe kpno noao edu 2347 n OBJECT Observation 1 1 script O3test sh New Integration Time s Status INTEGRATING Change Integration Time 466 0 504 0 271 0 307 0 443 0 485 0 619 0 675 5 e ADU o Read Noise 5 0 Se SC 580 0 630 5 569 0 611 0 421 0 467 0 ue 183 0 2210 Binning Read Out 5 19 383 0 419 0 383 0 419 0 Truss Temps D mscdisp n501376 1 LN y Individual Display zcombine none 55328 0 86096 0 55328 0 86096 0 imtool ADC Realy 70783 0 93580 4 70783 0 93580 4 74070 0 92403 0 74070 0 32403 0 68367 0 89965 4 68367 0 89965 4 4 Hr 4 59662 1 82626 0 59662 1 82626 0 70381 0 91489 0 70381 0 91489 0 69814 0 91581 4 69814 0 91581 4 X NOAO Mosaic 1 1 CCD Camera Mayall 4m Telescope OE DTE 10 69536 0 93672 0 69536 0 93672 0 Weather 11 72954 0 89954 0 72954 0 89954 0 nguiTraceSeq lt INFO gt name nguiLocals 0BS C 1 VAL element 0BS C 1 VAL op w 12 51432 0 80302 0 61432 0 80302 0 nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_12 VAL element 0BS_C_12 VAL 13 72873 0 91437 8 72873 0 91437 8 nguiTraceSeq lt INFO gt 085 C 9 VAL element 0BS
50. _C_9 14 73029 0 90993 0 73023 0 90993 0 nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_6 VAL element 0BS_C 15 71034 0 92669 4 71034 0 92669 4 nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_3_VAL element 0BS_ 16 65099 8 92314 2 65099 8 92314 2 nguiTraceSeq lt INFO gt name nguiLocals 0BS C 0 VAL 1 0 5 mscred gt nguiTraceSeq lt INFO gt name nguiLocals OBS 11 VAL element 0BS data mosaici 4m 20101026 een shot File Options nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_8 VAL element 0BS_ 1 09 50 nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_5 VAL element 0BS PS STI nquiTraceSeq lt INFO gt name nquiLocals O0BS C 2 VAL element 0BS_C 27 X nguiTraceSeq lt INFO gt name nquiLocals 0BS C 13 VAL element BS C 13 VAL nguiTraceSeq lt INFO gt name nguiLocals 0BS C 10 VAL element 0BS C 10 VAL dhs 0 gt result 0 nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_7_VAL element 0BS_C_7_VAL dhsi Metalata 10 0 nguiTraceSeq lt INFO gt name nguiLocals 0BS_C_1_VAL element 0BS C 1 VAL op w dhs hetaDat lines 142 e e nguiTraceSeq lt INFO gt name nguiLocals 0BS C 4 VAL element 0BS C 4 VAL dhs iMetallata expID 2455505 906468 nguiTraceSeq lt INFO gt name nguiLocals 0BS C 6 VAL 0 5 C 6 VAL op w dhsiiMetalata obsID bservation Number 1 e e NOCS xterm 1 Be nguiTraceSeq lt I
51. aic 1 1 image will appear to be nearly the same but don t be fooled it is not The new focal plane consists of eight e2v 2048 x 4096 CCDs and has essentially the same look as the old system However the CCDs are now read out using 16 amplifiers so the final MEF image will have 16 extensions not eight as in the previous camera The new Mosaic 1 1 images are a full 18 bit image large dynamic range linear to lt 0 5 up to 210 000 e and are 282 MB each The approximate bias level in normal gain mode is near 500 ADU and near 2500 ADU in logain mode In normal gain 1e DN the read noise is near five electrons and the CCDs are nearly blemish free a few bad columns in two edge devices The readout time is approximately 22 seconds and the display is very fast after that time so be prepared to gather substantial MBs of data We recommend you bring a large capacity external USB drive or a laptop with a big disk if you are planning to take your data home with you We also offer a logain mode 0 5 e ADU with a read noise of 3 5 electrons and read time of 34 seconds Binning of 1X1 and 2X2 are available as well 2X2 has a shorter readout time near eight seconds in normal gain mode and 14 seconds in logain mode The big difference you will be faced with is the new software The new CCDs and controller MONSOON are run from new software not the old ARCON system The new system to run Mosaic 1 1 is the NOCS NOAO Observation Control Software If
52. aic image at once There is an MSCCMD routine that acts as an interpreter allowing you to use traditional IRAF routines on the Mosaic files if you need to use additional IRAF routines One of the first things that you re likely to do is to stack sequences of zero dark and flat exposures to produce superimages to feed into CCDPROC the assumption that the darks and zeros are all the same using ZEROCOMBINE and DARKCOMBINE presents no complications On the other hand you are likely to want to scale the flats by their modes and this at present can be tricky Because of the importance of image defects modes and other statistics can be biased by bad values Normally a bad pixel mask will be available in the Mosaic database to improve the situation If you are after the ultimate in flat fielding you can 1 estimate the mode in two passes where the first pass restricted the range of allowable pixel intensities to plausible values and 2 the second pass used the mode from the first pass to limit the range of allowable values to between zero and twice the initial mode 59 With good zero dark and flat field images in hand basic image reduction is done with the MSCRED version of CCDPROC If your data consists of a dither sequence that you intend to stack later we recommend that you do not interpolate over bad pixels This is more logically done downstream as we discuss later One of the last basic steps that you may attempt is to bu
53. ames html 2 9 Atmospheric Dispersion Corrector at the 4 m only The Earth s atmosphere disperses the light from stars significantly when observing away from zenith The effect is greatest and similar at U and B where the stellar image is stretched for example 0 5 at a zenith distance of 452 1 4 airmasses and 0 9 at 602 2 airmasses The ADC prisms can be configured a rotation to counter this effect nearly completely thereby greatly reducing the elongation of the image introduced by the atmosphere Modes of Operations There are three modes that the ADC system can be used 1 Null mode where the ADCs make no correction 2 Track mode where corrections are periodically updated and 3 Preset mode where the corrections are preset at the beginning of an exposure to be correct for the middle of the exposure but otherwise not moved We recommend using Track mode to improve the image quality with a minimum of attention to the ADC operations ADC Filter Mode In Modes 2 and 3 Track and Preset the positions of the prisms are dependent on the observing bandpass because the optimum corrections have color dependent functionality Thus in using the ADC it is important to select the proper filter mode in the ADC GUI on 2 Note that this is done automatically when the ADCs are tracking While the ADC is not necessary to compensate for atmospheric dispersion when 28 using narrow band filters the guide cameras have
54. aneous Software Commands Most commands that are executed through various GUI buttons within the NOCS can also be executed on the command line on mosaic1 4m or mosaic1 36 For instance a start of the NOCS software can be executed either with the Start button on the Main Mosaic GUI or by issuing the command nocs start all from the command line when logged in as observer on mosaic1 4m or mosaic1 36 Below are several commands that may useful nocs status all displays the status of all NOCS processes nocs start stop all starts or stops the NOCS observing program nocs ping rack pings the NOCS rack to see if it s alive nocs status disk shows the disk usage nocs set project after the program ID has been set in the NGUI this updates the headers nocs start stop nics opens or closes the instrument control window filterwheel etc Nocs start stop ntcs opens or closes the telescope control system interface nocs start stop ngui opens or closes the NGUI window nocs start stop mccd opens or closes the MCCD and ADC windows nocsMode logain sets the gain to logain mode nocsMode normal sets the gain to normal gain mode nmslReset reinitializes the NMSL by doing the following a resets the systran fibre link b resets MONSOON c loads all default files in order to bring MONSOON to a known state d sets the operating mode normal or logain and enables the sequencer e applies voltages to the arrays after checking the s
55. ately 30 seconds and then typing nocs start all in the same window This should successfully start the NOCS software 11 5 The shutter returns to the dark position after every exposure There are 2 similar lines on the MCCD GUI see Figure 34 associated with the shutter One is labeled shutter the second is labeled ready The top line actually controls the shutter you can open or close the shutter or put it in the dark position from this line The second line indicates the state of the shutter after an exposure The shutter should return to the dark position after any calibration image a dark bias or dome flat For any sky observations the shutter should return to the guide position instead of dark If it doesn t you may need to click on the guide button for the shutter ready line the second shutter line of the MCCD GUI see Figure 34 After selecting this once it should always return the shutter to the guide position you may need to reselect this after a software restart Remember to put the shutter into the dark position at the end of the night from the top shutter line 11 6 L executed a script but nothing happened 79 It could be that system is simply waiting for the instrument to complete some movement the ADCs may be updating the filter track may be moving to the correct filter position or the system may be waiting on input from you Also check the xterm window from which you execu
56. autolog is another useful program to have This is an auto generated observing log which is very versatile allowing you to edit or place comments in any section of the log page To launch the autolog click on the Autolog button on the Main Mosaic GUI This will launch the KPNO Autolog Control Panel Error Reference source not found Figure 39 Be sure to enter exact path to your data directory select Mosaic as the instrument and click on Start Logging If Print log sheets automatically is selected a log page will be sent to the printer when the page is full 38 4meter Autolog Control Panel File Help Image directory data2 observer 20101024 Instrument Mosaic Start Logging d Print 109 sheets automatically 10 10 33 R Marzke Tel d 8 20 03 D Mills Figure 39 The Autolog Control Panel In the Image directory box you need to specify where the data is located The default location is data2 observer UTDATE Click on the Start Logging button to start the autolog program When any fits files are written to this directory they will be saved to the log The logs are then saved in your data directory as a postscript file VDU 4 m only The Video Display Unit displays all of the current telescope information To launch it simply double click on the icon on the Mayall 2 desktop labeled VDU 3 3 Ins and Outs of Scripting How to make a script All Mosaic 1 1 images are taken by ex
57. ce GUI shown in Figure 11 The CCD temperature displayed highlighted in blue is the chip mount plate temperature the CCDs themselves are not monitored and this is typically 10 C warmer than the CCDs themselves This temperature will remain constant within a few tenths of a degree as long as temperature control is maintained The CCD temperature display will turn red if the CCD temperature rises above 95 C as the CCD performance may be compromised above that temperature 16 LJ configuration 0 01 0 05 ADC Shutter ready dark j Ambient 7 12 6 Filter U Harris k1001 0 80 Dewar 2 178 6 CCD 1 106 7 DHE 4 35 3 Focus 8858 jPower 5 38 4 cse Figure 10 left The 1 1 instrument being vacuum pumped The Dewar 15 silver cylinder in the center above and behind the MONSOON electronics box Figure 11 right The MCCD graphical user interface is used to monitor temperature sensors located in the Dewar and electronics The Dewar tank is cooled to 170 C or cooler This temperature will begin to rise when 112 is exhausted If the Dewar temperature rises above 160 C the temperature display will turn red and mountain personnel will be notified via automatic email notification that the Dewar needs to be filled 2 3 The Data Acquisition System The eight CCDs 16 video channels are read out using a MONSOON CCD controller that includes an Orange de
58. des for many objects Due to the wide field and multi CCD nature of Mosaic there are several issues that may affect the accuracy of one s results and in particular the hope of achieving 1 photometry CCD to CCD sensitivity differences While flat fields remove the gross sensitivity differences across the CCDs each CCD exhibits its own spectral response Relative to the B band U sensitivity varies by up to 10 and V by 5 from CCD to CCD Consequently the color terms for one CCD are not applicable to data taken with another CCD At a minimum therefore one must know the color terms for each CCD But there is another quirk If data are taken in dithered mode then some stars may have been exposed across several different CCDs each with different spectral properties Photometry from the stacked image will be sensitive to the combination of color terms Variations in spectral characteristics on a single CCD Even across a single CCD there are variations in sensitivity approaching 4 U relative to B This problem though is not new The old TI and Tektronix CCDs also exhibit variations almost as large Shutter corrections The large shutter for Mosaic is not perfectly accurate That is a command for a 1 second exposure will not open the shutter across the entire array for exactly 1 000 seconds As of November 2003 a one second exposure held the shutter open for 0 97 seconds at the top of the array and 0 96 seconds at the bottom This
59. e EM ES EE File Process Status Real Tine Display Paths 8 Spdate Show Activity 8515 6 11518 4 11518 4 73 7843 3 11368 7 7843 3 11368 7 8 8908 9 12263 1 8908 9 12263 1 8585 4 11594 8685 4 11594 10 9002 1 11725 9 9002 1 11725 9 11 9014 8 12249 2 9014 8 12249 2 12 7760 2 11439 8 7760 2 11439 8 15 8772 2 11677 8 8772 2 11677 8 14 8450 5 12405 5 8450 5 12405 5 15 8071 4 10854 0 8071 4 10854 0 16 7764 5 11559 5 7764 5 11559 5 ecl mscexam image00889 ecl displsu image00898 ERROR task displsu not found ecl gt display image00888 ERROR FXF must specify which FITS extension image00898 gy jecl gt display 1 9 0089814 frame to be written into 1 16 1 r z1 549 5588 z2 502 8 ecl gt imexamine display frame 1 1 mit SECTION NPIX MEAN MEDIAN STDDEV MIN 376 380 1993 1997 25 581 7 581 3 68 577 SHE 378 382 1996 2000 25 582 585 5 006 573 409 413 2022 2026 25 582 4 582 4 204 573 Connect 427 431 2027 2031 25 582 4 582 5 612 572 480 484 2041 2045 25 582 7 584 5 677 571 499 493 1985 1989 25 584 594 5 544 575 527 531 1922 196 25 583 2 583 4 450 572 544 548 1918 1922 25 585 4 5865 4 192 579 553 557 1918 1922 25 585 2 5865 4 772 57 56
60. e Options Thu Nov 04 07 09 47 PM MST 2010 X NMSL Mosaic 1 1 Integration timer 6 0 8 0 Help 4m gwc kpno noao edu FOCUS Observation 7 7 focus 9550 Oc script FOCUSR sh Status ADC Ready Gain e ADU INTEGRATING 1 00 ixi New Integration Time 5 Change Integration Time Mode normali Read Noise 5 19 Read Out 5 CCD Temp 107 90 Figure 30 The NMSL GUI where most of the exposure information is displayed 2 NOAO Mosaic 1 1 CCD Camera Mayall 4m Telescope aka NGUI the script editor window eoo Hle Options NOAO Mosaic 1 1 CCD Camera Mayall 4m Telescope mocsParamsInit nocsParamsInit InocsParamsInit InocsParamsInit inocsParamsInit inocsParamsInit InocsParamsInit nocsParamsInit mocsParamsInit nguiShowFilter nquiShowFilter nguiShowFilter InquishowFilter ingquiShowFilter InquiShowFilter nquiShowFilter inguiShowFilter nquiShowFilter nguiShowFilter ngquiShowFilter nquiShowFilter inguishowFilter nguiShowFilter lt INFO gt lt INFO gt lt INFO gt lt INFO gt lt INFO gt lt INFO gt lt INFO gt lt INFO gt lt INFO gt 1 dummy nocs dummy nocs dummy nocs dummy nocs dummy nocs dummy nocs dummy nocs obj registered OK lamp registered OK telpost registered OK telofft registered OK focus regi
61. ecuting a script Yes even a test exposure There is a very easy to use script editor within the NOCS called the NGUI Mosaic 1 1 CCD Camera Mayall 4m Telescope File Options Help nocsParamsInit INFO dummy nocs obj registered OK nocsParamsInit INFO dummy nocs lamp registered nocsParamsInit INFO dummy nocs telpost registered OK nocsParamsInit INFO dummy nocs telofft registered nocsParamsInit INFO dummy nocs focus registered nocsParamsInit INFO dummy nocs gpxps registered nocsParamsInit INFO dummy nocs scr registered nocsParamsInit INFO dummy nocs rbin registered nocsParamsInit INFO dummy nocs cbin registered nguiShowFilter 1 X U X U X ignore ignore X k1001 B Harris ignore ignore X k1002 V Harris ignore X ignore X k1003 Harris ignore ignore 1004 Nearly Mould X ignore X ignore X k1005 ha H alpha X ignore X ignore X k1009 X hal6 H alpha l6nm X ignore ee X k1013 5055 X ignore X ignore X k1017 SDSS X ignore ignore X 1018 1 5055 M ignore X ignore k1019 2 SDSS M ignore ignore k1020 VR Bernstein X ignore X ignore X k1040 Us solid U 1044 X ignore ignore Ud Dey 1045 X ignore ignore 5 D nguiShowFilter nguiShowFilter nguiShowFilter nguiShowFilter Brownian Motion L Telescope Commands Filter Commands TwilightFlat Object MosGrid
62. ed pixels for the variable pixel scale Use of this option should only be invoked when this information is preserved in the flattened images to begin with The final step is to combine the re projected dither set images using MSCSTACK This is the stage where careful attention must be paid to variations in zero point and sky level among the images Even on photometric nights the sky level is likely to change over the course of the dither sequence You can use the image modes to track the sky level but again one must be careful that the mode is not biased by bad pixels and defects You can for example calculate the average sky level for a dither sequence and then gave MSCSTACK a file specifying additive offsets for each image about this average At this stage you should also account for any photometric 62 variations among images MSCSTACK can also accept a of multiplicative offsets These might be based on an atmospheric extinction curve on photometric nights or determined by comparing stars among the dither set Or you can specify a relatively representative image section and have MSCSTACK compute the modes The final stacking of the image by MSCSTACK can be done with any of the standard combining algorithms within the IRAF combine tasks Some of us prefer to use an average value with sigma rejection We also make complete use of the bad pixel map at this stage to eliminate known defects One might be tempted to use a simple median
63. empting to reduce their data The guides also provide a thorough description of all MSCRED tasks that may be valuable during the night s observing 53 The NOAO Mosaic data format produced is multi extension FITS MEF The file contains seventeen FITS header and data units HDU The first HDU called the primary or global header unit contains only header information which is common to all the CCD images The remaining sixteen HDUs called extensions contain the images from the eight CCDs The fact that the image data are stored as FITS format images is not particularly significant A single FITS format image file may be treated in the same way as any other IRAF image format The significant feature is the multi image nature of the data format This means that commands that operate on images must have the image or images within the file specified Only commands specifically intended to operate on MEF files such as those in the MSCRED package can be used by simply specifying the file name Commands that operate on files rather than images such as copying a file may be used on files In general it is safest to use only MSCRED commands on files IRAF V2 11 is required to run MSCRED As of January 31 2011 we are running IRAF V2 15 as well as the latest version of MSCRED on mosaic1 4m mosaic1 36 mayall 2 mayall 3 and emerald The basic syntax for specifying an image MEF file to an IRAF task 15 filename extensio
64. erNoTelescope sh rw rw r 1 observer users 76 Nov 5 00 10 standard sh rwxrw r x 1 observer users 2720 Nov 4 20 20 TESTR sh To change the standard sh file to become executable note the lacking x s at the beginning of the line simply type chmod standard sh 43 Download a copy of NGUI Observers new to the upgraded Mosaic may find it useful to download NGUI to practice creating observing scripts The latest version of NGUI can be downloaded from the Mosaic web sites http www noao edu kpno mosaic A README file is also available from the link above indicating how to install this on your system The same version of NGUI is also available at the telescope for creating scripts on the fly Note that while this downloadable copy of NGUI is useful for practice in making scripts any script you create from this will likely not work at telescope NGUI uses the filter position number instead of the filter name in creating scripts and the list of filters in this demo version of NGUI may not be the same as what will be in the filter track during your run For example the R filter may be in position 4 in the demo version but in position 6 during your run So if you create a script using this demo version to take images in the R filter and ran that script at the telescope you may have images in some other filter Filters are changed frequently and currently there is no way to get list of exact filter positions for your run in advance
65. es The reduction of Mosaic camera images at first glance is just like that of any other CCD camera ignoring the immense amount of data contained in a single Mosaic image As is standard for other cameras reduction requires overscan correction followed by zero and flat field corrections In detail however full reduction of Mosaic data requires a number of steps not normally encountered in the routine reduction of other CCD camera images The driving factor in Mosaic reduction is the expectation that the observer will not simply obtain a single Mosaic exposure of an astronomical field but may want to construct a deep integration from several Mosaic images spatially offset or dithered from each other to cover both the gaps between the individual CCDs and any defects Stacking dithered Mosaic images places high demands on the uniformity of the initial data reduction as well as requiring several additional steps once the basic reduction of the individual exposures is complete See Buell Jannuzi s Draft Guide to NOAO Deep Wide Field Survey MOSIAC Reductions http www noao edu noao noaodeep ReductionOpt frames html for more 58 information on Mosaic data reductions The Mosaic camera also has a spatially variable pixel scale that has important implications for ensuring a uniform photometric zeropoint in the reduced images 46 Calibration Data to Obtain at the Telescope Good data reduction begins with obtaining good calibration data at the
66. etup and adds in the grid type Three grid types are available Random RAxDec and From File These grid patterns work as described in the dither section 51 3 6 Shutting things down and restarting Sometimes things go awry and you need to restart the NOCS software To do so click on the Stop button on the main Mosaic GUI This should close all of the NOCS windows Wait until you see Ready in the Main Mosaic GUI before restarting the NOCS software At the end of the night there is no need to shutdown the NOCS software Please leave it running Also put the shutter into the dark position on the MCCD GUI at the end of every night 52 4 0 Evaluating Recording and Reducing Mosaic Images In this section we discuss the software and observing procedures needed for the following 1 How to evaluate the observations as they are obtained at the telescope including how to display Mosaic images how to evaluate the telescope focus and edit and examine the image headers We also discuss how to log the observations 2 How to read and write the data from to tape 3 Calibration observations that should be obtained at the telescope 4 How to reduce the images Observers familiar with CCD cameras and the IRAF reduction and analysis software will find the processing of Mosaic images to be similar to cameras of more modest size At the same time there are a number of important differences that we touch upon briefly here To start with
67. ext the individual CCDs in a Mosaic exposure There are many display options that are discussed in the help page The only special factor in using this task with the Mosaic data is that you must specify which image to display using the image extension syntax discussed previously As an example to display the central portion of extension im3 i e CCD 3 in the first frame and the whole image in the second frame cl gt display obj123 3 1 fill cl gt display obj123 3 2 fill The MSCDISPLAY task is based on DISPLAY with a number of specialized enhancements for displaying Mosaic data It displays the entire Mosaic observation in a single frame by filling each image in a tiled region of the frame buffer The default filling defined by the order parameter sub samples the image by uniform integer steps to fit the tile and then replicates pixels to scale to the full tile size The resolution is set by the frame buffer size defined by the stdimage variable example command is cl mscdisplay obj123 1 Many of the parameters in MSCDISPLAY are the same as DISPLAY and there are also a few that are specific to the task of displaying a mosaic of CCD images The mapping of the pixel values to gray levels includes the same automatic or range scaling algorithms as in DISPLAY This is done for each image in the mosaic separately The parameter zcombine then selects whether to display each image with it s own display range none or to combine t
68. ffset 200 300 testnics offset 500 300 testnics offset 600 300 providing all telescope offsets performed by that dither script At this point you can copy the numbers into your notebook or into a file At present we do not have NOCS control of the guider We have incorporated a pause and acknowledgement for reacquiring a guide star Between dither positions it is necessary for the observing assistant to disable guiding while the telescope offsets The NOCS will wait for you to acknowledge that guiding has been reacquired Once the observing assistant has re enabled guiding click the enter key in the xterm window where the script was executed There is also no sound alert yet when the telescope has moved to a new dither position so the user needs to be watchful of this to alert the observing assistant as to the new move These shortcomings in the dither procedure are a work in progress MOSgrid The MOSgrid script provides the ability to image over a grid on the sky while at each point in the grid performing any of the dither patterns just discussed Figure 42 shows an example MOSgrid which used an RAxDec grid and the basic FillGap dither The script performed a 2 x 2 grid and at each grid position the quincunx pattern of the FillGap dither can be seen The dithers used by MOSgrid are exactly those of MOSdither In fact when you look at the MOSgrid GUI see Figure 52 you will see that it simply repeats the dither scripting s
69. ghtly larger than the previous SITe CCD focal plane Due to this a slight vignetting is seen on the north and south edges of the array This vignetting is symmetric at each side and shows 690 light decrease at 100 columns from the north or south edge and a 1596 decrease in light when 25 columns in from an edge Figure 6 below shows a 20 line sum at the southern edge of CCD 4 segment 12 The vignetting is removed by flat fielding X irafterm rre redeas Figure 6 as seen on the right edge of chip 4 13 Fringing Fringes are seen in I and z band images obtained with Mosaic 1 1 and the e2v CCDs The fringe pattern appears to be identical in I and z band in terms of its structure and location on each of the CCDs The level is approximately 100 ADU in normal gain mode in both filters corresponding to a deviation from the local mean sky for the fringes of lt 1 in counts Figure 7 Highly stretched I band image showing the fringe pattern This image taken during commissioning also shows trails for each star as the telescope was moving slightly during the exposure Below is a line plot showing an average of 10 lines in the I band fringe image The fringes are seen as the small bumps in the background light The large feature near column 220 is a star TM iud tify deht Figure 8 Line plot of I band image showing fringing Different Gain modes 14 There are two observing
70. h 3 monitors and a small web camera Emerald is a Linux computer with 2 monitors To launch the necessary windows and start up the system double click on the 31 Mosaic icon Figure 24 on desktop of 2 or emerald This will bring up Main Mosaic GUI Figure 25 CH MOSAIC Figure 24 The Mosaic Desktop Icon to launch the Main Mosaic GUI X Mosa Mosaic Menu Ready Start Stop Autolog CCD GUI Start Stop 4 Figure 25 The Mosaic GUI Click on Start to start the NOCS software this is equivalent to typing nocs start all on 1 This will bring up several windows many of which will be minimized on the dock at the bottom of the monitor The last window to appear will be the NGUI or script editor window titled NOAO Mosaic 1 1 CCD Camera Note that when starting the NOCS software it checks to see if the software is running elsewhere first The software cannot be started locally if it is already running While the software loads the NOAO Mosaic Status All window see Figure 26 will update in real time as parts of the system are started Once everything is loaded this window will disappear 32 NOAO Mosaic Status exit 44 Figure 26 The NOCS Mosaic Status All window which disappears when the software is fully loaded When all of the windows are up the left hand monitor should look similar to this Finder File Edit
71. he display ranges into a single display range based on the minimum and maximum values the average of the minimum and maximum values average or the median of the minimum and maximum values The independent scaling may be most appropriate for raw data while the minmax scaling is recommended for processed data Another optional answer here is auto which is the default and will try to use the best option given the status of the data MSCDISPLAY offers a special mode of display not previously available If invoked before the readout of the Mosaic array is complete MSCDISPLAY will begin painting the XIMTOOL screen with as much data as are available at that moment When automatic gray level scaling is used it will compute the scaling based on the amount of data present when it starts It will then keep the same scaling for the number of display and sleep cycles given by the niterate parameter after which it will 55 compute new display scaling and reload all currently recorded data Thus small value for the niterate parameter will update the scaling frequently and a large value will update more infrequently The trade off is that calculating the scaling takes a significant amount of time and causes the whole display to be reloaded while using only the first scaling based on just a little bit of data may result in poor scaling values Generally we recommend infrequent updates because of the very lengthy time requ
72. his can only be done while an exposure is in progress and not during readout Pause Resume Abort and Stop are all also available from within the NMSL window but only available while integrating These fields are grayed out and disabled during readout and when idle When an exposure is paused you can only select Resume From there you can either continue with the exposure select Stop which will stop the exposure and readout or select Abort which will stop the exposure and discard the image One can also change the gain from the NMSL window by clicking on either the Normal Mode button or the Logain Mode button These buttons are grayed out and disabled during readout and integration but can be used when the system is idle See Table 2 in Section 1 1 for detector characteristics for normal and logain modes To abort a script click Ctrl C in the xterm window from which you executed the currently running script You should see the following message 46 NOCS xterm 1 DITSCMD_24d9snohstnohsDramaNewObs DONE SUCCESS 1 TASK nohs ACTION nohs_newobs BRGS headers DITSCMD_24datnmslinms DramaInit DONE DITSCHD 24dbznmslinmslDrama6pxSetAVPz DONE SUCCESS 1 TASK nmsl ACTION nmsl_gpxSetAYP ARGS exp1D 2455493 0298305680043995 DITSCHD 24dcznmslznmslDramalInitz DONE DITSCHD 24dd nmslznmslDramaGpxbetState DONE OK SUCCESS 1 TASK nmsl ACTION nmsl_gpxGetState ARGS IGNORE DITSCHD 24ffznmslznmslD
73. ic filter is mapped to the ideal filter mode so there is no need to manually select the filter mode The default mode for each filter is listed at http www noao edu kpno mosaic filters filter names 29 The 3 ADC modes in more detail are 1 Null Mode The ADC prisms are set to a fixed position that makes no correction for the atmosphere 2 Track Mode The positions of the ADC prisms are automatically updated ata periodic rate typically 60 second intervals to account for the changing zenith and azimuth directions of the telescope as it moves e g as it tracks during an observation or slews to a new position 3 Preset Mode The positions of the ADC prisms are set to a pre determined location as demanded by the mid point of the exposure In this mode movement of the ADC prisms is synchronized with the data acquisition sequence In this mode the ADC prisms do not move during the exposure 30 3 0 SOFTWARE The software used to operate Mosaic 1 1 is called the NOAO Observation Control System NOCS NOCS is a script based software package meaning all of the data taking will be done through a script that has been created most likely by the observer A Script editor is a part of the software package making it simple to create scripts as you observe 31 Mosaic 1 1 computers Several computers work together to obtain Mosaic 1 1 data Although the observer should only need to access the computers mosaic1 and mayall 2 at the 4
74. ich yields pixels of essentially constant angular size over the extent of the Mosaic field This is also the best point to fold in knowledge of the bad pixel map The bad pixel map itself can be re gridded by MSCIMAGE giving the final routine MSCSTACK complete knowledge of where the bad pixels are If the bad pixels had been replaced prior to this point and had not been flagged in the Mosaic images themselves their locations would have been unavailable in the final stacking Some of us prefer to clear out the bad pixels right at the beginning of the CCDPROC process Re gridding the Mosaic images requires a method to calculate new pixels interpolated from the original ones One can select from any number of the standard IRAF interpolation routines however given the immense quantity of the data involved we have always selected bilinear interpolation for speed considerations Unfortunately bilinear interpolation smoothes the noise slightly and as the new pixel grid beats against the original grid the noise in the tangent plane image shows bands of coherent noise structure This will be reduced somewhat in the final stacked image given the spatial de coherence of the images in the dither set Choosing the sinc interpolator significantly reduces the coherence but takes several times longer to process and may introduce a characteristic ringing around bad pixels Lastly as noted above MSCIMAGE has the option to correct the flux in the re gridd
75. ield At the 4 m the fields are approximately 1440 arcsec north and south of the center of the science field At the 0 9 m the fields are approximately 2400 arcsec north and south of the center of the science field TV focus can be moved remotely offsets are 0 9 and 1 7 at the 4 m and 0 1 and 1 9 at the 0 9 m for the north and south TVs respectively At a given location suitable guide stars are almost always available without moving the telescope from the desired position We find that we can guide at the 4 m on stars as faint as V 20 in full moon and at the 0 9 m to V 17 near full moon The TVs and guider are controlled by the telescope operator at the 4 m but by the observer at the 0 9 meter The observer must first select the N or S TV on the distribution panel See Figure 20 For the selected TV on the ICCD Control Panel 1 Turnthe high voltage potentiometer completely counterclockwise 10 turn pot Toggle the power switch on on TV screen pixel defects will appear Neutral density switch should be down off Push the momentary button to enable high voltage Slowly turn the high voltage potentiometer clockwise monitoring TVs until guide stars appear Acquire a guidestar on the computer moss and initiate guiding consult the 0 9 m telescope user s guide http www noao edu 0 9m Tel Op html for details on step 6 ET ow De When switching between the two TVs sure to turn high voltage potentiomete
76. ild a sky flat or illumination correction from a portion of your reduced data You could try going directly to a sky flat without any prior reduction with a dome flat or any other serviceable flat but working with roughly flattened data first allows for more accurate estimation of the mode in the presence of faint astronomical sources and further allows for better detection and rejection of biased regions of the images At the same time flat field reductions will produce wild values in the few defect regions so extra care is required when estimating modes or other statistics from flattened data 48 Variable Pixel Scale and Zero Point Uniformity A key assumption in traditional reduction of CCD images is that the pixel scale is uniform and that a properly reduced blank sky image will have a uniform and flat appearance This is not correct when the pixel scale varies over the field In the case of Mosaic the pixel scale decreases approximately quadratically from the field center with the pixels in the field corners being 6 smaller in the radial direction and 8 smaller in area given the complete astrometric description of the field Pixels in field corners thus would properly report only 92 of the sky level seen in the field center even with uniform sensitivity At the same time the same number of total photons would be detected from a star regardless of how many pixels the PSF would be distributed over Forcing the sky to be uniform over
77. imit limit limit Image Size 8592x8192 pix 4496x4096 pix 8592x8192 pix 4496x4096 pix with 50 pixel 282 Mbytes 74 Mbytes 282 Mbytes 74 Mbytes overscan Table 2 Observing Modes and Mode Specific Characteristics 1 2 KPNO Mayall 4 Meter Parameters Count Rates approx for now At UBVRI 20th Mag 0 43 B 376 V 340 R 390 1 262 36 36 XIMTOOL display orientation North left East down 0 26 pixel at center decreases quadratically by 6 5 out to corners Image Quality The flatness of the focal plane appears to be very good The PSF variations across the entire field of view have a 1 sigma value center to corner of about 0 1 pixels FWHM The star images are nice and round everywhere in the field Bad column in 5 section 5 861 864 CCD8 1022 1023 Typical Focus 8700 at 18C etc liquid U filter is 300 units different ADC Atmospheric Dispersion Correction For broad band filters use ADC in track mode with appropriate filter selected For flat fields and narrow band exposures use the null position or closest in wavelength broad band filter mode Vignetting Mosaic 1 1 is slightly wider 5 than Mosaic 1 0 and shows a 690 light decrease at 100 columns from the north or south edge and a 1596 decrease in light when 25 columns from the edge The vignetting is removed by flat fielding Table 3 KPNO 4 Meter Characteristics 1 3 WIYN 0 9 Meter formerly KPNO 0 9 m Parameters
78. in stacking the reduced Mosaic images is to register them to a common coordinate system This is done with the MSCZERO and MSCCMATCH programs The MSCZERO routine can be used to set the coordinate system origin for any given image given a known position or even ad hoc position for any star MSCCMATCH produces a revised astrometric solution for each dithered image This is essential because of small linear shifts during the dither process and because of rotations introduced by differential atmospheric refraction across the field There are three important uses of MSCZERO The first is to set the coordinate zero point fairly accurately and then read back coordinates With a reference star one can obtain useful real time coordinates at the telescope The second use of MSCZERO is to identify a list of stars in one fiducial image that will be located in the other images in the dither set A third use is to reset the origins of the other images in the dither set to match the fiducial image in the event that the coordinate origin is lost or corrupted as happened a few times in our reductions The MSCZERO routine uses the known astrometric description of the Mosaic field so that the location of any star identified can be used to set a global origin In passing we note that the quality of the astrometric solution is excellent stars can be located to a fraction of a pixel 0 26 at the 4 m in all portions of the field MSCCMATCH uses the astrometric solu
79. ired to display an entire image This use of MSCDISPLAY is only sensible if automatic displaying is disabled from the DHS The MSCDISPLAY task is automatically started when a new image is reading out The Data Handling System DHS controls this default behavior Whether to display or not is controlled by the DHS user interface see Section 3 4 4 3 Examining the Data Once you have displayed the Mosaic exposure you will need a few more commands specific to Mosaic to interact with the display to do such things as looking at exposure levels checking the focus and so on Just as we have written MSCDISPLAY as a special version of DISPLAY we provide the MSCEXAMINE routine as an analog of the standard IMEXAMINE to allow for interactive examination of Mosaic images MSCEXAMINE is essentially the same as the standard IMEXAMINE task except that it translates the cursor position in a tiled mosaic display into the image coordinates of the appropriate extension image Line and column plots also piece together the extensions at the particular line or column of the Mosaic display To enter the task after displaying an image the command is cl mscexam As with IMEXAMINE one may specify the Mosaic MEF filename to be examined and if itis not currently displayed it will be displayed using the current parameters of MSCDISPLAY To modify the radial plot parameters in MSCEXAMINE type cl rimexam2 which is analogous to rimexam for IMEXAMINE Or you
80. l Version 1 3EXPORT 1924 85 1612 97 2 36 05 Figure 62 A saturaged image 11 After starting the NOCS software upon executing the first script you may get an error like this FAILURE TASK nohs ACTION nohs_newobs ARGS headers If you see this error type nocs start nohs an xterm window that is logged in to mosaic1 4m mosaic1 36 12 Never abort a Focus sequence 13 Do not pause an exposure for longer than of the entire exposure time as this can cause problems with the software If you need to pause for a longer time use Stop instead which will stop the exposure and read it out 14 In a mosdither sequence the NOCS system waits until after an image has readout before offsetting instead of offsetting during readout 77 11 APPENDIX G TROUBLESHOOTING Listed below some problems that have been seen with Mosaic In some cases we have known solutions in other cases the solutions are more magical 11 1 The ADC does not seem to be reacting fast enough The ADC GUI does not respond instantaneously to the motion of the ADC prisms There is a time delay If you restart ARCONS the GUI will occasionally not even show the normal positions of the prisms but as soon as you turn on either of the non null modes and or move the telescope the display will update Similarly you might start an exposure and hear the shutter open before you see the ADC GUI update the positions of the
81. ld The 0 9 m scale is 0 425 per pixel The spatial variation is small with the scale decreasing to 0 420 per pixel at the corner of the field 27 Ghost Pupil When using narrow band interference very blue e g U or red e g I Z band filters at the 4 m a faint image of the telescope pupil falls on the CCD and has a diameter of about 10 arcmin Depending on the bandpass and construction of the filter this reflection typically manifests itself at lt 1 for broad band to 2 4 narrow band OII Ha U I 7 level above the background It arises from an internal reflection off the front surface of the rear element of the corrector despite the use of an extremely good anti reflection AR coating Our investigation suggests that similar 4 element correctors currently in use should exhibit a similar effect and tests performed by Alistair Walker with the CTIO 4 m confirm this analysis Although the ghost pupil can subjectively appear severe when viewed at high contrast for narrow band filters photometric accuracy is preserved when this additive term is removed during the reductions One can avoid the affected region on the Mosaic array by moving the telescope slightly if there is any concern about the reduction process For a description of how to correct for pupil ghost images in your observations you can read the discussion in the NOAO Deep Wide Field Survey MOSAIC Reduction Cookbook http www noao edu noao noaodeep ReductionOpt fr
82. ls 5696 of the total sky area At the 4 m 4 inch filters illuminate approximately 5 5K x 5 5K pixels 4696 of the total sky area The positioning of the filter track is highly repeatable However the acceleration of the track can occasionally dislodge dust particles between filter moves particularly if intervening movements have turned the filter upside down In all cases the filter track software moves the track in the direction that minimizes the distance moved to reach the requested filter position In addition to the 14 position filter track there is a manual slide that can hold a single filter of the same size 5 75 inches square This may be used for example to hold a bandpass filter when polarization filters are used in the track Use of an additional hand insert filter changes the focus At the 4 m changing inserting or removing this filter can only be done at the maintenance Southeast Annex position 2 6 Filters For Mosaic To fully utilize the field of view of the 8K x 8K filters must be 5 75 inches 146 mm square and have 5 43 inches 138 mm clear aperture The optimum thickness that preserves image quality over the entire field of view 15 0 47 inches 12 0 mm KPNO Mosaic filters adhere to these specifications to maintain a parfocal condition Thus neither the telescope nor the guide TVs should require a focus change when switching between filters There is one exception the 504 U filter k1001 for which
83. ls in the imaging system The video channels on a given CCD 1 the left and right outputs have a crosstalk level of about 0 2 This is shown in Figure 9 as classic crosstalk The crosstalk between video channels from different CCDs is less than 0 1 for adjacent CCDs and insignificant for all other channels The imaging system also exhibits a trailing 15 ghost anomaly where full well saturated stars produce a ghost image that trails Star in the readout direction i e along the row away from the output amplifier This anomaly is not currently understood and remains a feature of the system Figure 9 Image of full well saturated stars showing the effects of crosstalk between CCD outputs and the trailing ghost anomaly 2 2 The Dewar The Mosaic Dewar is a large 6 3 liter vacuum vessel Figure 10 that is radiatively and conductively coupled to the CCD chip mount The conductive coupling between the tank and the CCD chip mount has been tuned to allow the temperature of the CCDs to be regulated at around 110 C over a wide ambient temperature swing The CCD temperature is regulated by a Lakeshore temperature controller that is configured for a maximum heater power of five watts The hold time of the Dewar is typically 13 5 hours and must be filled by an observing technician at the start and end of each night Several temperatures within the Dewar are monitored and displayed in the Mosaic MCCD Graphical User Interfa
84. lter changes setting the telescope focus etc Note It is essential that you select Guide in the ready line above at the beginning of the night 6 ADC control 4 m only the ADC controls GUI ADC Co N 5 _Glck to show full window Figure 35 The ADC GUI minimized Click on the yellow bar to interact with the ADCs 7 Aterminal window a window logged in to mosaic1 used for editing and executing scripts NOCS xterm 2 1 4 18 cd exec bserver mosaicl 4m exec TESTb 4 Figure 36 xterm window useful for typing NOCS commands 37 Other Handy Programs 7 Mosa Mosaic Menu Ready Start Stop 4 Figure 37 The Mosaic GUI TRUSS TEMP 4 m only A useful program to launch is the Truss Temperature GUI This will display the current 4 meter truss temperature mirror temperature and ambient temperature Normally all 3 temperature display boxes are green but when the truss temperature varies by more than 1 degree since the program was launched or reset it will turn red indicating it might be time to check telescope focus To launch the program click on the Truss Temps button on the Main Mosaic GUI Truss_temp Oct 23 16 54 55 2010 Truss Temp Mirror Temp Ambient Temp Figure 38 The Truss Temperature program tacking the telescope Truss temperature AUTOLOG The
85. modes available normal and logain The normal mode is optimized for shorter read time and greater dynamic range The gain of the normal mode has been tuned to allow the full dynamic range of the MONSOON controller 18 bit ADCs to sample the full well capacity of the e2v CCDs gt 200 000 e The logain mode is optimized for low noise performance at the expense of read time and dynamic range The following tables show the performance characteristics of the CCDs in the different observing modes CCD Z CCD FITS Gain Read Noise Saturation 96 Dark Signal Amplifier Extension ADU Level pix hr 226800 99 9985 221400 99 9984 218400 99 9984 217300 99 9986 218400 99 9984 224700 99 9985 218400 99 9985 217300 99 9986 215250 99 9986 217900 99 9987 215250 99 9988 215250 99 9988 218400 99 9985 219350 99 9984 211150 99 9986 216300 99 9986 Table 5 Normal mode CCD operating characteristics CCD FITS Gain Read Noise Saturation Amplifier Extension e ADU e Level e 123208 99 9985 125829 99 9984 120586 99 9984 120586 99 9986 120586 99 9984 123208 99 9985 123208 99 9985 128451 99 9986 123208 99 9986 123208 99 9987 123208 99 9988 128451 99 9988 123208 99 9985 128451 99 9984 128451 99 9986 115343 99 9986 Table 6 mode CCD operating characteristis Dark Signal E e pix hr HCTE Crosstalk There is some crosstalk between video channe
86. moving the telescope east MOSdither Scripts MOSdither is a script that allows the user to obtain dithered observations of a field of view This type of observation might be used to eliminate the gaps in the focal plane or as a method of greater area coverage for your specific observing program MOSdither offers a variety of dither patterns to choose from These are summarized in Table 9 FillGap Performs a five point dither starting at the current position 8Q Places a central object in each of the eight CCDs Takes N exposures in a user defined RA by DEC grid Takes N random location exposures within in a user defined RA by Dec box Dithers as instructed by a user supplied dither table Table 9 Dither files defined FillGap This is a minimal dither pattern providing five dither positions based on the telescope offsets listed in Table 10 This dither pattern is the old lauer dat dither pattern slightly adjusted to compensate for the larger chip gaps The last exposure is taken at the starting point and the telescope is left here at the end of the dither sequence The appearance of this dither pattern is shown in Figure 42 48 477 92 v o o OH d ce Figure 44 A schematic map of a MOSgrip dither which used a 2 x 2 RADec grid where each point used a FillGap 5 point dither Table 10 The default FillGap dither offsets 80 This dither pattern is usef
87. n where filename is the name of the file The fits extension does not need to be used The extension is the name of the image For the NOAO Mosaic data the sixteen CCD images have the names im1 through im16 but the simple 1 through 10 works too The extension position in the file where the first extension is 1 may also be used To access the global header for listing or editing the extension number is 0 i e filename 0 There is currently no wildcard notation for specifying a set of extensions So to apply an arbitrary IRAF command that takes a list of images you must either prepare an 015 or type the list explicitly or use the special MSCCMD command The task MSCCMD takes an IRAF command with the image list parameter replaced by the special string input The input list of Mosaic files will then be expanded to a list of image extensions Section 4 3 illustrates the use of MSCCMD with the HSELECT task 54 4 2 Displaying and Evaluating Images at the Telescope During observing a small set of IRAF commands are commonly used to examine the data This section describes these common commands While this section is oriented to examining the data at the telescope during the course of observing the tools described here would also be used when later reducing data The two commands DISPLAY and MSCDISPLAY are used to display the images in XIMTOOL or DS9 The DISPLAY task is used to display individual images in this cont
88. nds and pick three steps in RA and four steps in Dec your grid would look like the figure below and be repeated two times Each X position will be 300 arcseconds apart For even steps the dither sequence averages the positions about the center of the field For odd numbers of steps one grid point will lie at the center RA lt gt XXX X X X DEC up and down XXX XXX From File This option provides the user with the ability to perform a custom dither The script asks for a filename the file needs to be placed in the home directory and will offset 50 the telescope and Dec to each position specified in the The has simple ASCII format of one absolute offset per line in arcsec as shown in the above examples The script produces an offset that is an exposure for each line in the file Once ended the script returns the telescope to the starting position Some General and Highly Useful Bits of Information All offsets those in the fixed dither pattern scripts and those in the calculated dither scripts are stored in the script only The telescope offsets are written into the FITS header for each offset but no file of the offsets is produced If you wish to keep the dither values you can retrieve them from the script as follows If you have a dither script named mydither dat and you want to get the set of offsets used in that dither typing grep offset mydither dat will produce a listing such as testnics o
89. o provide very fast control of the shutter This design allows the TV guide fields to be shuttered independently of the science field In the guide mode the closed shutter still allows the TV guide cameras to see the sky In the dark mode these fields are closed as well The acquisition software controls which mode the shutter remains in between exposures For object observations the shutter goes to the guide mode before the exposure begins For requested observation types of dark flat or zero the shutter goes to the dark mode before the exposure begins and remains in this mode after the exposure and readout are completed Note that the TV fields are always open when the shutter is open the different shutter modes only control the TV fields when the science shutter is closed If you have been taking darks flats or zeros you may need to set the shutter mode to guide in order to get light to the TV guide camera The time for the blades to move completely across the field is 23 msec There is a 115ms delay from the time the DHE issues the shutter open close command until the shutter actually moves This delay does not affect the exposure time since it is the same for both open and closing The DHE has a built in readout delay of 150 ms to allow the shutter to fully close before the CCDs are read out The motion of the shutter blades during both opening and closing are in the same direction so the exposure level is nearly constant over the array The
90. on Like most of the CCD reduction tasks you can also select only a certain type of exposure for listing Examples of the two modes are 57 Summary for all exposures cl gt ccdlist fits extname im1 Summary for all object exposures cl gt ccdlist fits extname im1 ccdtype object List of all extensions cl gt ccdlist obj123 4 4 Getting your Mosaic Data Home Mosaic images are 282Mb each With the short readout time it is common to get 300 images per night which amounts to approximately 85Gb of data per night We no longer support writing data to tape CD or DVD Instead we recommend bringing a portable USB hard drive or transferring your data to a laptop At the KPNO 4 meter there are easily accessible USB ports on the left sides of the mayall 2 and mayall 3 monitors to allow you to easily and quickly backup your data Just plug it in and drag and drop to get your data on your hard drive IMPORTANT Make sure the hard drive is formatted for writing to a Mac At the WIYN 0 9 meter emerald has USB access in the computer room Other possible methods of getting your data are via FTP or the NOAO archive Remember you will likely have large amounts of data and the FTP transfer will take a significant time to complete All Mosaic data is archived in the NOAO Science Archive Information on retrieving your Mosaic data can be found at http portal nvo noao edu documentation query noaoquery html 4 5 The Reduction of Mosaic Imag
91. r counterclockwise and turn off high voltage on the TV no longer in use 25 ICCD B SOUTH ICCD A NORTH amp 1 2 2 H9IH 330119 8 METER ACQUISITION TV SYSTEM Figure 20 A schematic drawing of the layout of the TV control panels at the 0 9 m Only the two left most panels in the lower rack are used with the Mosaic TVs The upper rack is used to select which TV video signal is seen on the monitor 2 8 Correctors The 4 m corrector is a 4 element fused silica for maximum U band efficiency design with additional internal prisms that serve as an atmospheric dispersion corrector ADC See Figure 21 for the optical layout and refer to Jacoby et al 1998 SPIE 3355 721 for a detailed description of the corrector and ADC Hy H ui HHHH M Figure 21 The 4 m corrector optical layout All elements are made from fused silica except for the ADC components which are made from LLF6 7 LLF6 and UBK7 as viewed from left to right At the right are the science filter Dewar window and CCD from left to right The ADC elements appear in the middle as four planar elements although they are wedged 26 The 0 9 m corrector is simple 2 element fused silica design There is ADC at 0 9 m See Figure 22 for the optical layout Figure 22 The 0 9 m corrector optical layout Both elements are made from fu
92. ramaInitz DONE DITSCHD 2503 exit status 2DITS F SIGINT DITS Exited via exit handler with signal SIGINT lt lt ABANDONED gt gt home observer exec standards_d sh at line 101 executing ditscmd nmsl nmsl apxStartExp If you were INTEGRATING you should do the following If you were NOT integrating you re probably to continue anyway 20080312 observer mosaici d4m exec E Figure 43 The procedure for recovering from an aborted script Be sure to follow the on screen procedure before continuing The executed command in step 3 may be hard to read but should be ditscmd nohs nohs endobs 47 Image Display Images are automatically displayed in the Ximtool within the DHS window You can examine the data with Iraf within the DHS window or you can view the images on mayall 2 or emerald outside of the DHS window Iraf DS9 and Ximtool are all available on mayall 2 and emerald The mosaic1 data directory is mounted onto mayall 2 as data mosaic1 4m and emerald as data mosaic1 36 so your data is easily accessible 3 5 Dithering Dithering with Mosaic 1 1 One of the most powerful tools available to the Mosaic 1 1 user is the ability to perform dithers and group these together into grid patterns of dithers These tasks are accomplished by using the MOSdither and MOSgrid scripts offsets used in the dither are in units of arcseconds with moving the telescope north and
93. rive on the computer named 1 while users will generally run the entire system from the Mac mini mayall 2 at the 4 m or Linux computer emerald at the 0 9 m in the control room Users can run IRAF and ds9 and perform full data manipulations and reductions on mayall 2 4 m or emerald 0 9 m in the control room both of which have the data directory cross mounted Images 282 Mbytes each and a typical night of 300 images will produce about 85 Gbytes Be aware that ftping this amount of data to your home computer may take many hours and is likely to time out fail or be killed by the next observer if done on your last morning We highly recommend bringing a large USB drive to plug into one of the Mac minis and perform nightly data transfers The Mosaic 1 1 data are all archived and users may also obtain their data from the NOAO archive Data are written in a Multi Extension Fits Format MEF There are 16 extensions one for each CCD amplifier and one global header the 0 extension see Figure 1 If you want to work with or display only one of the 16 extensions commands such as display 3 and imcopy Image 14 ext14 fits would work Once the 16 extensions are combined by merging the amplifiers only eight extensions exist and are equal to the CCD number itself ccbs cape 5 2013 8 16 EAST Figure 1 The display orientation of the 16 sections of the
94. scopes at Kitt Peak National Observatory KPNO In 2010 the controllers and CCDs for Mosaic 1 1 were upgraded While the basic design of the instrument remains the same 8k x 8k imager with 15 micron pixels the operation and characteristics have changed significantly so please take the time to at least review the current characteristics General Characteristics silicon with 2 layer AR Size 8192 x 8192 18 bits plus header overscan 282Mbytes Pixels Size 15 um 0 26 pixel at the 4 m 0 43 pixel at the 0 9 m See Table See Table 2 38 350nm 78 400nm 82 500nm 80 650nm 63 900nm average for eight CCDs also see Figure 3 Section 2 1 Dark 4 4 hr average for sixteen outputs 2 CCD CCDGaps 1 2 mm 80 pixels in both row and column dimensions Cosmetics Excellent only three bad columns on entire array very good pixel response uniformity and sensitivity Filters 5 75 x 5 75 parfocal 34 filters now available at KPNO http www noao edu kpno mosaic filters filters html Normal and Low Gain modes available See Table 2 Good to 0 596 from the bias level up to saturation See Table 2 Table 1 General Mosaic 1 1 Characteristics Observing Normal Normal Low Gain Low Gain Readout Time 22 seconds 11 seconds 38 seconds 17 seconds Overhead 1 2 e ADU 0 47 ADU Read Noise 32e Saturation 218 CCD 312Ke ADC 124 ADC 124 ADC full well l
95. sed silica At the right are the science filter Dewar window and CCD from left to right Coatings and Scattered Light All optics have been coated with very broad band multi layer anti reflection coatings to improve photon collection efficiency and to reduce scattered light Surface losses are 10 from below 35004 to longward of 95004 at the 4 m and better at the 0 9 m In addition all interior structural surfaces have been blackened to minimize scattered light Tests at the telescope indicate that the new correctors suffer significantly less than the old correctors from scattering Nevertheless with the very wide fields being imaged bright stars are inevitable producing some ghosting from bright objects in certain fields Image quality The 4 m images are excellent across the entire 35 x35 field On good nights we have documented uniform 0 65 images in R There is no measurable focus gradient or PSF variation to within 1096 The 0 9 m telescope is not as well corrected There is a small focus gradient across the 59 x59 field amounting to 20 30 focus units Images in the corners of the mosaic degrade somewhat especially in the lower left corner 1 Also the corners of the field are slightly vignetted 5 10 by the internal telescope baffle Image Scale The 4 m scale is slightly variable 6 396 due to pincushion distortions from 0 261 per pixel at the center f 3 1 to 0 245 per pixel 3 3 at the corner of the fie
96. separate broad band filters See Section 2 6 that will see the effects of atmospheric dispersion Differential refraction between the guider and the science CCDs will change as a function of telescope position and will cause blurring for long exposures at high zenith distances if the ADC is set to Null Mode In this case the observer should select an ADC Filter Mode that encompasses both the narrow band filter and the TV camera filter bandpasses and select ADC mode 2 or 3 track or preset Note that this is done automatically if the ADCs are in use The ADC GUI Control of the ADC prisms and modes is selected via the ADC GUI see Figure 23 The status of the ADC prisms also is displayed in the GUI window The primary user parameters in the GUI that concern the observer are the ADC Mode Null Track Preset and ADC Filter Mode U I 1 ADC Configuration Filter Mode filter verification prompts R filter Help View log H Observing Mode w E Null Preset Track 60 E 0 04 x 358 84 6 Re index S Last ADC adjustment occurred at 14 36 53 MST Last re index at 16 33 35 Sep 1 to minimize window RA 0 14 27 59 DEC 16 23 38 7 Telescope azimuth 123 18 Zenith angle 72 38 Filter R Harris k1004 Moving ADC to optimal position please wait Figure 23 The ADC GUI The Filter Verification prompts option has been disabled Be assured that every Mosa
97. simple a sequence as makes sense for dithered Mosaic images taken under good conditions I CCDPROC to correct for cross talk trim overscan bias subtraction and flat fielding IIL MSCZERO apply a uniform astrometric zeropoint to all images of all colors a sequence dithered or not Identify a star in each frame and set its zeropoint to be identical III MSCZERO using the w key identify 10 20 stars per CCD in one of the frames in the sequence IV MSCCMATCH correct for rotations and minor zeropoint offsets I run this interactively to be sure the solutions are good V MSCIMAGE select a single image that will serve as a reference for all other 63 images of this field other images will then have correct geometry for stacking and later comparison VI MSCSTACK add up the dithered sets VILIMCOPY up to this point you have created single images constructed from the five or more images in each of the dithered sets Because each image stared at a different piece of sky there will be offsets between the images and each image may have a unique size I use IMCOPY to select a region of each image that is common to all images In effect IMCOPY provides a fast method to shift all the final images to a common astrometric system using integer pixel shifts You may also use IMSHIFT to apply a fractional pixel shift but this introduces another interpolation that I have not found necessary 64 5 0 APPENDIX A Miscell
98. stered OK gpxps registered OK scr registered OK dummy nocs rbin registered dummy chin registered U X ignore ignore X k1001 B Harris ignore X ignore k1002 V Harris M ignore X ignore k1003 Harris X ignore X ignore X 1004 Nearly Mould ignore X ignore X 1005 X ha H alpha X ignore X ignore k1009 6 VM ha hal g 5055 X ignore X ignore X k1017 Xr SDSS X ignore X ignore X 1018 X i SDSS X ignore X ignore X 1019 SDSS X ignore ignore X k1020 X VR Bernstein X ignore X ignore X 1040 X Us solid U 1044 X ignore ignore Ud Dey k1045 X ignore X ignore PREPPY CO 1 Is CO gt KE X 03 Us Ud hal6 H alpha l6nm X ignore X ignore X k1013 Help _ Brownian Motion Telescope Commands Filter Commands _____ TwilightFlat Object MosGrid Test Refresh Filter s Set Project Exit l NGUI 20101011 C 2010 AURA Inc Contact Philip Daly pnd noao edu Figure 31 The NGUI provides the creation of scripts 35 3 VNC mosaic 1 4m monsoon the VNC window with DHS control and image display VNC 1 4 1 monsoon m ee Data Handling Sustem Supervisor NOAD IRAF XImtool Version 1 3EXPORT File View Options mosaicl_ 023 RTD RS du Display Prim Load Seve Info Til
99. t configuration GUI A simple script looks like this observer mosaic1 4m exec more DflatV sh bin sh FileName home observer exec DflatV sh H Object DflatV Script DflatV NumObs DA Filter 3 V k1003 MONSOON intTime 45 MONSOON row bin 1 MONSOON col bin 1 A send project parameters to the KTM set project read common function s and set trap MOSAIC_SBIN nocs functions sh 41 trap trapSignal home observer exec DflatV sh LINENO SIGINT SIGTERM Starting script home observer exec DflatV sh ditscmd init ditscmd nmsl wgui Argument1 Starting script home observer exec DflatV sh checkReturnValue nmsl nmsl wgui Starting script home observer exec DflatV sh set intTime ditscmd nmsl init ditscmd nmsl gpxSetAVP Argument1 intTime 45 checkReturnValue nmsl gpxSetAVP intTime 45 set row bin ditscmd nmsl nmsl init ditscmd gpxSetAVP Argument1 rowBin 1 checkReturnValue nmsl gpxSetAVP rowBin 1 set col bin ditscmd nmsl nmsl init ditscmd gpxSetAVP Argument1 colBin 1 checkReturnValue nmsl gpxSetAVP colBin 1 set expVector ditscmd nmsl nmsl init ditscmd nmsl gpxSetAVP Argument1 expVector 1 checkReturnValue 5 nmsl nmsl gpxSetAVP expVector 1 set filter ditscmd nics nics init ditscmd nics nics filter Argument1 3
100. tector head electronics box DHE coupled to a Pixel Acquisition Node computer PAN through a Giga bit fiber link The DHE is located on the instrument see Figure 12 and the PAN mosaicipan 4m at 4 m or 36 at the 0 9 m is located in the computer room see Figure 13 The MONSOON DHE PAN controls the detector voltages and clock sequences necessary to operate and read out the Mosaic CCDs In addition the data acquisition system includes a supervisor computer mosaic1 4m at the 4 m or mosaic1 36 at the 0 9 m that is the main user interface and a data handling computer mosaicidhs 4m at the 4 m 1 36 at the 0 9 m These computers are also located in the computer room and share the same rack as the PAN computer 17 Figure 12 The MONSOON Detector Head Electronics DHE box with the access cover removed to reveal the chassis and PCB cards The DHE mounted on the Mosaic 1 1 instrument ts shown installed at prime focus of the KPNO 4 meter Figure 13 The Mosaic 1 1 computer rack containing the user interface and supervisor computer the Pixel Acquisition Node computer the Data Handling System computer and a spare computer The rack also contains a KVM switch and a remote power controller 18 2 4 The CCD Shutter The shutter consists of a pair of opposing sliding blades one of which has rectangular slots open for the guide field The blades are attached to pneumatically driven cylinders t
101. ted your script there may be either a Failure or Error message indicating what the problem is If the filter failed to move to the correct position the script will die with an error message indicating such 11 7 It takes too long for the primary mirror to settle during a mosdither 4 m only During a mosdither sequence the NOCS software waits until your image is readout before offsetting to the new position In addition to the time to offset and setup ona new guide star there may also be a delay to starting your next exposure due to the primary mirror support system The primary mirror has an active support system aka 4MAPS If your offsets are in a mosdither sequence are large the support system may need to adjust some of the forces on the mirror which may take several seconds to update and display on the Observing Assistant s computer If you are doing a rapid fire program these delays can add up and cost your program a significant amount of time The Observing Assistant is able to control whether or not these updates occur during a mosdither sequence ask your friendly OA to disable this if necessary 11 8 I can t take an image because the filter track won t lock into place The NOCS system will not take an exposure unless a filter is in position any script will die following a filter move failure If there are problems with the filter track and a filter will not lock into place ie the locking pins will not insert there
102. tion and recorded relative telescope offsets to locate the registration stars in a given image It can also be assisted by running the images through MSCZERO if this assumption fails for some reason Once a given star is located it is cross correlated with the same star in the fiducial image to 61 calculate a positional offset You have option to review quality of the match to decide if it is acceptable The final offset is the average of the individual offsets with a check for outliers This interactive approach gives the best confidence that the correct offsets are being used but the entire process can be run in an automated fashion Also MSCCMATCH can access a position catalog and interactively display the known stars on the Mosaic image to provide a totally independent solution for each dithered frame The penultimate step in stacking Mosaic images is to re grid them into common tangent plane projections using MSCIMAGE The use of a common projection aligned to the centers of the pixels is done so that the shift and stack step does not require any further re sampling Up to this point the individual CCD images are each stored in their own partition in the multi extensions FITS files MSCIMAGE pastes the individual CCDs into a large single FITS image accounting for their accurate relative positions and rotations given the astrometric description of the field MSCIMAGE further re grids the pixels into a tangent plane projection wh
103. u will be asked whether or not you would like to overwrite the previous script All scripts are saved in the exec directory home observer exec Note that the shortest integration time allowed is 0 2 seconds and the longest exposure time allowed is 3600 seconds 40 Good script writing Its a good idea to name your script something logical to you and something not too long You will need to call that script by tying the name so keep it simple It s also a good idea to enter the Object Name as something meaningful to you and that observation What you enter here is the Title keyword in the header Executing a script To execute a script make sure you are in the home observer exec directory where all of the scripts are saved by default and type the name of the script preceded by To execute a script called ZERO sh type ZERO sh If you have trouble executing that script be sure that you are in the correct directory script exists with that name the script is an executable file Editing a script Any script can be edited e g to change the exposure time or filter except the default Mosaic scripts those denoted by a lower case m at the beginning of the name Use your text editor of choice to edit the file While one can edit scripts it is really only advisable for very experienced users Scripts are text files but are not simple therefore it s not advisable to make a script outside of the NGUI scrip
104. ul for observations such as photometric standard stars where the observer wishes to place objects on each of the eight Mosaic 1 1 CCDs The eight dithers in this script move the object sequentially onto each CCD in the following order 5 6 7 8 4 3 2 1 The script assumes the starting point has the object of interest at or near the center of the field of view 8Q dithers the telescope according to the offsets listed in Table 11 When finished the script returns the telescope to the starting position 49 4 meter 0 9 RA 898 Table 11 The default 8Q dither offsets Random This dither pattern moves the telescope to N random positions within a maximum offset of the user supplied RA and Dec limits Each of the positions are randomly generated and offset from the initial starting position but can be no larger than the RA and Dec limits specified The user sets how many random positions observations are desired and the script returns the telescope to the starting point when finished If Brownian motion is selected the random walk will eventually drift off center If Brownian motion is FALSE the random offsets are centered around the starting field position RAxDec Using user supplied RA DEC step sizes this script obtains N iterations of an N x M grid centered on the starting position The number of grid points in each iteration is an input value For example if you choose to do two iterations of 300 x 300 arcseco
105. xec DflatV sh H Default Mosaic scripts Several default Mosaic scripts are available in the home observer exec directory These are all labeled with a preceding lower case m e g mBias sh mBias sh a single bias exposure mBias_9 sh 9 bias exposures mTESTR sh a single test image in R assuming position 4 at 10 seconds mDark50s sh a single dark frame with 60 second exposure time Stringing scripts together to make a super script You may find it useful to string several scripts together to make observing more efficient To do so simply create a new file that contains each script on a separate line For instance if you want to string five dither sequences together one for each filter to execute the five individual scripts in sequence your file may look like this observer mosaic1 4m exec more standard ch DitherSA92Us sh DitherSA92B sh DitherSA92V sh DitherSA92R sh DitherSA92I sh Make sure this file is executable You can check this by typing 15 l in the home observer exec directory You should see something like this rwxrw r x 1 observer users 11151 Nov 5 04 57 mBias Och rwxrw r x 1 observer users 2545 Nov 5 04 56 mBias sh rwxrw r x 1 observer users 2584 Nov 5 04 59 mDARK60s sh rwxrw r x 1 observer users 13439 Nov 2 14 27 MOSDITHER sh rwxrw r x 1 observer users 2726 Nov 5 04 58 mTESTR sh rwxrw r x 1 observer users 2720 Nov 4 21 43 O3test sh rwXxrw r x 1 observer users 13454 Nov 4 15 41 pndDith
106. xposure is reading out the countdown clock will be orange and the Status line will display Reading Out When the data is being written to disk the countdown clock will be red negative numbers and the Status line will display Transferring Negative numbers are expected and OK The transfer should only take few 3 seconds If it takes longer than this look in your xterm window or the text window in the NMSL to see if any errors or failures occurred If errors failures have occurred and your image did not automatically display in the DHS Ximtool window you may need to restart the NOCS The Data Handling System DHS After an exposure has read out and transferred you should see your image appear in the DHS Ximtool window where you can interact with the data There should also be an Iraf window within the DHS VNC window it maybe minimized as cl click on the icon and click restore The DHS Paths amp Files tab is where you can change your image file prefix as well as the directory where your data is being stored To change these values type in the new information and be sure to click the corresponding Apply button see Figure 48 in Appendix E Note 1 new directory is automatically created for each night when the system is re started For the directory to be automatically created you must restart the NOCS software To force the creation of the directory without a restart of the system type obsdir on the command line
107. ystem state is OK 65 6 0 APPENDIX Differential Refraction With the wide field of the Mosaic imager one should be aware of the special conditions imposed by differential atmospheric refraction during exposures Gary Bernstein motivated this section Arcsec Differential Retraction Ajimass Figure 45 A plot showing the differential prismatic distortion due to atmospheric refraction over the extent of the Mosaic field The difference in angular displacement of a star between the center and corner of the Mosaic array is shown as a function of airmass for the 4 m and 0 9 m cameras Note that this effect does not vanish at the zenith as even the angular extent of the Mosaic field at the zenith is large enough for differential prismatic distortion to be present The particular curves shown are for an STP atmosphere The actual displacement will vary with temperature and in general will be slightly lower given the altitude of KPNO The prismatic distortion will also occur only parallel to a vector pointing to the horizon the center to corner displacement is thus meant only to be representative of typical angular distances within the Mosaic field Note that as a Mosaic field transits a range of airmasses as might occur in a dither sequence the differential prismatic distortion will vary over the sequence 66 7 0 APPENDIX Issues About Photometery A common goal of observing with Mosaic is to derive photometric magnitu

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